diff --git a/.changeset/hip-singers-vanish.md b/.changeset/hip-singers-vanish.md
deleted file mode 100644
index 9dce4d98a8..0000000000
--- a/.changeset/hip-singers-vanish.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': minor
----
-
-feat: SSR-safe ID generation with `$props.id()`
diff --git a/.changeset/short-fireants-talk.md b/.changeset/short-fireants-talk.md
new file mode 100644
index 0000000000..c26bdc9c8b
--- /dev/null
+++ b/.changeset/short-fireants-talk.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ignore typescript abstract methods
diff --git a/documentation/docs/06-runtime/03-lifecycle-hooks.md b/documentation/docs/06-runtime/03-lifecycle-hooks.md
index a3dbe04b00..2b97ca796f 100644
--- a/documentation/docs/06-runtime/03-lifecycle-hooks.md
+++ b/documentation/docs/06-runtime/03-lifecycle-hooks.md
@@ -45,8 +45,6 @@ If a function is returned from `onMount`, it will be called when the component i
 
 ## `onDestroy`
 
-> EXPORT_SNIPPET: svelte#onDestroy
-
 Schedules a callback to run immediately before the component is unmounted.
 
 Out of `onMount`, `beforeUpdate`, `afterUpdate` and `onDestroy`, this is the only one that runs inside a server-side component.
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index e112bf6209..ff3b08fe7a 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,23 @@
 # svelte
 
+## 5.20.0
+
+### Minor Changes
+
+- feat: SSR-safe ID generation with `$props.id()` ([#15185](https://github.com/sveltejs/svelte/pull/15185))
+
+### Patch Changes
+
+- fix: take private and public into account for `constant_assignment` of derived state ([#15276](https://github.com/sveltejs/svelte/pull/15276))
+
+- fix: value/checked not correctly set using spread ([#15239](https://github.com/sveltejs/svelte/pull/15239))
+
+- chore: tweak effect self invalidation logic, run transition dispatches without reactive context ([#15275](https://github.com/sveltejs/svelte/pull/15275))
+
+- fix: use `importNode` to clone templates for Firefox ([#15272](https://github.com/sveltejs/svelte/pull/15272))
+
+- fix: recurse into `$derived` for ownership validation ([#15166](https://github.com/sveltejs/svelte/pull/15166))
+
 ## 5.19.10
 
 ### Patch Changes
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index a4594b2a5c..bea1efd7b4 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.19.10",
+  "version": "5.20.0",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
diff --git a/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js b/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
index 18c805128d..09eb0bfa68 100644
--- a/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
+++ b/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
@@ -118,6 +118,12 @@ const visitors = {
 		delete node.implements;
 		return context.next();
 	},
+	MethodDefinition(node, context) {
+		if (node.abstract) {
+			return b.empty;
+		}
+		return context.next();
+	},
 	VariableDeclaration(node, context) {
 		if (node.declare) {
 			return b.empty;
diff --git a/packages/svelte/src/compiler/phases/2-analyze/types.d.ts b/packages/svelte/src/compiler/phases/2-analyze/types.d.ts
index 14b14f9c84..70796a0d59 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/types.d.ts
+++ b/packages/svelte/src/compiler/phases/2-analyze/types.d.ts
@@ -19,7 +19,7 @@ export interface AnalysisState {
 	component_slots: Set<string>;
 	/** Information about the current expression/directive/block value */
 	expression: ExpressionMetadata | null;
-	derived_state: string[];
+	derived_state: { name: string; private: boolean }[];
 	function_depth: number;
 
 	// legacy stuff
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js
index 41144fc74c..42e4498969 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js
@@ -23,11 +23,6 @@ export function Attribute(node, context) {
 		if (node.name === 'value' && parent.name === 'option') {
 			mark_subtree_dynamic(context.path);
 		}
-
-		// special case <img loading="lazy" />
-		if (node.name === 'loading' && parent.name === 'img') {
-			mark_subtree_dynamic(context.path);
-		}
 	}
 
 	if (is_event_attribute(node)) {
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
index ed397258f8..0463e4da85 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
@@ -7,7 +7,7 @@ import { get_rune } from '../../scope.js';
  * @param {Context} context
  */
 export function ClassBody(node, context) {
-	/** @type {string[]} */
+	/** @type {{name: string, private: boolean}[]} */
 	const derived_state = [];
 
 	for (const definition of node.body) {
@@ -18,7 +18,10 @@ export function ClassBody(node, context) {
 		) {
 			const rune = get_rune(definition.value, context.state.scope);
 			if (rune === '$derived' || rune === '$derived.by') {
-				derived_state.push(definition.key.name);
+				derived_state.push({
+					name: definition.key.name,
+					private: definition.key.type === 'PrivateIdentifier'
+				});
 			}
 		}
 	}
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js
index 2d90c85364..1507123e13 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/shared/utils.js
@@ -1,4 +1,4 @@
-/** @import { AssignmentExpression, Expression, Literal, Node, Pattern, PrivateIdentifier, Super, UpdateExpression, VariableDeclarator } from 'estree' */
+/** @import { AssignmentExpression, Expression, Identifier, Literal, Node, Pattern, PrivateIdentifier, Super, UpdateExpression, VariableDeclarator } from 'estree' */
 /** @import { AST, Binding } from '#compiler' */
 /** @import { AnalysisState, Context } from '../../types' */
 /** @import { Scope } from '../../../scope' */
@@ -38,16 +38,22 @@ export function validate_assignment(node, argument, state) {
 			e.snippet_parameter_assignment(node);
 		}
 	}
-
 	if (
 		argument.type === 'MemberExpression' &&
 		argument.object.type === 'ThisExpression' &&
 		(((argument.property.type === 'PrivateIdentifier' || argument.property.type === 'Identifier') &&
-			state.derived_state.includes(argument.property.name)) ||
+			state.derived_state.some(
+				(derived) =>
+					derived.name === /** @type {PrivateIdentifier | Identifier} */ (argument.property).name &&
+					derived.private === (argument.property.type === 'PrivateIdentifier')
+			)) ||
 			(argument.property.type === 'Literal' &&
 				argument.property.value &&
 				typeof argument.property.value === 'string' &&
-				state.derived_state.includes(argument.property.value)))
+				state.derived_state.some(
+					(derived) =>
+						derived.name === /** @type {Literal} */ (argument.property).value && !derived.private
+				)))
 	) {
 		e.constant_assignment(node, 'derived state');
 	}
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
index 7b3a9a4d0e..ed800e5226 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
@@ -190,22 +190,21 @@ export function ClassBody(node, context) {
 				'method',
 				b.id('$.ADD_OWNER'),
 				[b.id('owner')],
-				Array.from(public_state)
-					// Only run ownership addition on $state fields.
-					// Theoretically someone could create a `$state` while creating `$state.raw` or inside a `$derived.by`,
-					// but that feels so much of an edge case that it doesn't warrant a perf hit for the common case.
-					.filter(([_, { kind }]) => kind === 'state')
-					.map(([name]) =>
-						b.stmt(
-							b.call(
-								'$.add_owner',
-								b.call('$.get', b.member(b.this, b.private_id(name))),
-								b.id('owner'),
-								b.literal(false),
-								is_ignored(node, 'ownership_invalid_binding') && b.true
-							)
+				[
+					b.stmt(
+						b.call(
+							'$.add_owner_to_class',
+							b.this,
+							b.id('owner'),
+							b.array(
+								Array.from(public_state).map(([name]) =>
+									b.thunk(b.call('$.get', b.member(b.this, b.private_id(name))))
+								)
+							),
+							is_ignored(node, 'ownership_invalid_binding') && b.true
 						)
-					),
+					)
+				],
 				true
 			)
 		);
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
index 2e61ca8abe..2b76330c1a 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js
@@ -300,11 +300,6 @@ export function RegularElement(node, context) {
 	build_class_directives(class_directives, node_id, context, is_attributes_reactive);
 	build_style_directives(style_directives, node_id, context, is_attributes_reactive);
 
-	// Apply the src and loading attributes for <img> elements after the element is appended to the document
-	if (node.name === 'img' && (has_spread || lookup.has('loading'))) {
-		context.state.after_update.push(b.stmt(b.call('$.handle_lazy_img', node_id)));
-	}
-
 	if (
 		is_load_error_element(node.name) &&
 		(has_spread || has_use || lookup.has('onload') || lookup.has('onerror'))
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
index fde88877dc..dc15e479cb 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
@@ -204,37 +204,18 @@ export function build_component(node, component_name, context, anchor = context.
 			const expression = /** @type {Expression} */ (context.visit(attribute.expression));
 
 			if (dev && attribute.name !== 'this') {
-				let should_add_owner = true;
-
-				if (attribute.expression.type !== 'SequenceExpression') {
-					const left = object(attribute.expression);
-
-					if (left?.type === 'Identifier') {
-						const binding = context.state.scope.get(left.name);
-
-						// Only run ownership addition on $state fields.
-						// Theoretically someone could create a `$state` while creating `$state.raw` or inside a `$derived.by`,
-						// but that feels so much of an edge case that it doesn't warrant a perf hit for the common case.
-						if (binding?.kind === 'derived' || binding?.kind === 'raw_state') {
-							should_add_owner = false;
-						}
-					}
-				}
-
-				if (should_add_owner) {
-					binding_initializers.push(
-						b.stmt(
-							b.call(
-								b.id('$.add_owner_effect'),
-								expression.type === 'SequenceExpression'
-									? expression.expressions[0]
-									: b.thunk(expression),
-								b.id(component_name),
-								is_ignored(node, 'ownership_invalid_binding') && b.true
-							)
+				binding_initializers.push(
+					b.stmt(
+						b.call(
+							b.id('$.add_owner_effect'),
+							expression.type === 'SequenceExpression'
+								? expression.expressions[0]
+								: b.thunk(expression),
+							b.id(component_name),
+							is_ignored(node, 'ownership_invalid_binding') && b.true
 						)
-					);
-				}
+					)
+				);
 			}
 
 			if (expression.type === 'SequenceExpression') {
diff --git a/packages/svelte/src/internal/client/dev/ownership.js b/packages/svelte/src/internal/client/dev/ownership.js
index 2a2527803a..62119b36db 100644
--- a/packages/svelte/src/internal/client/dev/ownership.js
+++ b/packages/svelte/src/internal/client/dev/ownership.js
@@ -6,7 +6,7 @@ import { render_effect, user_pre_effect } from '../reactivity/effects.js';
 import { dev_current_component_function } from '../context.js';
 import { get_prototype_of } from '../../shared/utils.js';
 import * as w from '../warnings.js';
-import { FILENAME } from '../../../constants.js';
+import { FILENAME, UNINITIALIZED } from '../../../constants.js';
 
 /** @type {Record<string, Array<{ start: Location, end: Location, component: Function }>>} */
 const boundaries = {};
@@ -140,6 +140,25 @@ export function add_owner_effect(get_object, Component, skip_warning = false) {
 	});
 }
 
+/**
+ * @param {any} _this
+ * @param {Function} owner
+ * @param {Array<() => any>} getters
+ * @param {boolean} skip_warning
+ */
+export function add_owner_to_class(_this, owner, getters, skip_warning) {
+	_this[ADD_OWNER].current ||= getters.map(() => UNINITIALIZED);
+
+	for (let i = 0; i < getters.length; i += 1) {
+		const current = getters[i]();
+		// For performance reasons we only re-add the owner if the state has changed
+		if (current !== _this[ADD_OWNER][i]) {
+			_this[ADD_OWNER].current[i] = current;
+			add_owner(current, owner, false, skip_warning);
+		}
+	}
+}
+
 /**
  * @param {ProxyMetadata | null} from
  * @param {ProxyMetadata} to
@@ -196,7 +215,19 @@ function add_owner_to_object(object, owner, seen) {
 			if (proto === Object.prototype) {
 				// recurse until we find a state proxy
 				for (const key in object) {
-					add_owner_to_object(object[key], owner, seen);
+					if (Object.getOwnPropertyDescriptor(object, key)?.get) {
+						// Similar to the class case; the getter could update with a new state
+						let current = UNINITIALIZED;
+						render_effect(() => {
+							const next = object[key];
+							if (current !== next) {
+								current = next;
+								add_owner_to_object(next, owner, seen);
+							}
+						});
+					} else {
+						add_owner_to_object(object[key], owner, seen);
+					}
 				}
 			} else if (proto === Array.prototype) {
 				// recurse until we find a state proxy
@@ -221,9 +252,10 @@ function has_owner(metadata, component) {
 	return (
 		metadata.owners.has(component) ||
 		// This helps avoid false positives when using HMR, where the component function is replaced
-		[...metadata.owners].some(
-			(owner) => /** @type {any} */ (owner)[FILENAME] === /** @type {any} */ (component)?.[FILENAME]
-		) ||
+		(FILENAME in component &&
+			[...metadata.owners].some(
+				(owner) => /** @type {any} */ (owner)[FILENAME] === component[FILENAME]
+			)) ||
 		(metadata.parent !== null && has_owner(metadata.parent, component))
 	);
 }
diff --git a/packages/svelte/src/internal/client/dom/elements/attributes.js b/packages/svelte/src/internal/client/dom/elements/attributes.js
index 4a0f0cea0e..2dba2d797a 100644
--- a/packages/svelte/src/internal/client/dom/elements/attributes.js
+++ b/packages/svelte/src/internal/client/dom/elements/attributes.js
@@ -399,15 +399,18 @@ export function set_attributes(
 				if (name === 'value' || name === 'checked') {
 					// removing value/checked also removes defaultValue/defaultChecked — preserve
 					let input = /** @type {HTMLInputElement} */ (element);
-
+					const use_default = prev === undefined;
 					if (name === 'value') {
-						let prev = input.defaultValue;
+						let previous = input.defaultValue;
 						input.removeAttribute(name);
-						input.defaultValue = prev;
+						input.defaultValue = previous;
+						// @ts-ignore
+						input.value = input.__value = use_default ? previous : null;
 					} else {
-						let prev = input.defaultChecked;
+						let previous = input.defaultChecked;
 						input.removeAttribute(name);
-						input.defaultChecked = prev;
+						input.defaultChecked = previous;
+						input.checked = use_default ? previous : false;
 					}
 				} else {
 					element.removeAttribute(key);
@@ -520,28 +523,3 @@ function srcset_url_equal(element, srcset) {
 		)
 	);
 }
-
-/**
- * @param {HTMLImageElement} element
- * @returns {void}
- */
-export function handle_lazy_img(element) {
-	// If we're using an image that has a lazy loading attribute, we need to apply
-	// the loading and src after the img element has been appended to the document.
-	// Otherwise the lazy behaviour will not work due to our cloneNode heuristic for
-	// templates.
-	if (!hydrating && element.loading === 'lazy') {
-		var src = element.src;
-		// @ts-expect-error
-		element[LOADING_ATTR_SYMBOL] = null;
-		element.loading = 'eager';
-		element.removeAttribute('src');
-		requestAnimationFrame(() => {
-			// @ts-expect-error
-			if (element[LOADING_ATTR_SYMBOL] !== 'eager') {
-				element.loading = 'lazy';
-			}
-			element.src = src;
-		});
-	}
-}
diff --git a/packages/svelte/src/internal/client/dom/elements/transitions.js b/packages/svelte/src/internal/client/dom/elements/transitions.js
index b3c16cdd08..fbc1da95df 100644
--- a/packages/svelte/src/internal/client/dom/elements/transitions.js
+++ b/packages/svelte/src/internal/client/dom/elements/transitions.js
@@ -14,6 +14,7 @@ import { current_each_item } from '../blocks/each.js';
 import { TRANSITION_GLOBAL, TRANSITION_IN, TRANSITION_OUT } from '../../../../constants.js';
 import { BLOCK_EFFECT, EFFECT_RAN, EFFECT_TRANSPARENT } from '../../constants.js';
 import { queue_micro_task } from '../task.js';
+import { without_reactive_context } from './bindings/shared.js';
 
 /**
  * @param {Element} element
@@ -21,7 +22,9 @@ import { queue_micro_task } from '../task.js';
  * @returns {void}
  */
 function dispatch_event(element, type) {
-	element.dispatchEvent(new CustomEvent(type));
+	without_reactive_context(() => {
+		element.dispatchEvent(new CustomEvent(type));
+	});
 }
 
 /**
diff --git a/packages/svelte/src/internal/client/dom/operations.js b/packages/svelte/src/internal/client/dom/operations.js
index e75b5ed862..45263382a8 100644
--- a/packages/svelte/src/internal/client/dom/operations.js
+++ b/packages/svelte/src/internal/client/dom/operations.js
@@ -13,6 +13,9 @@ export var $window;
 /** @type {Document} */
 export var $document;
 
+/** @type {boolean} */
+export var is_firefox;
+
 /** @type {() => Node | null} */
 var first_child_getter;
 /** @type {() => Node | null} */
@@ -29,6 +32,7 @@ export function init_operations() {
 
 	$window = window;
 	$document = document;
+	is_firefox = /Firefox/.test(navigator.userAgent);
 
 	var element_prototype = Element.prototype;
 	var node_prototype = Node.prototype;
diff --git a/packages/svelte/src/internal/client/dom/template.js b/packages/svelte/src/internal/client/dom/template.js
index 3e4f45aba8..6ff3b0fa19 100644
--- a/packages/svelte/src/internal/client/dom/template.js
+++ b/packages/svelte/src/internal/client/dom/template.js
@@ -1,6 +1,6 @@
 /** @import { Effect, TemplateNode } from '#client' */
 import { hydrate_next, hydrate_node, hydrating, set_hydrate_node } from './hydration.js';
-import { create_text, get_first_child } from './operations.js';
+import { create_text, get_first_child, is_firefox } from './operations.js';
 import { create_fragment_from_html } from './reconciler.js';
 import { active_effect } from '../runtime.js';
 import { TEMPLATE_FRAGMENT, TEMPLATE_USE_IMPORT_NODE } from '../../../constants.js';
@@ -48,7 +48,7 @@ export function template(content, flags) {
 		}
 
 		var clone = /** @type {TemplateNode} */ (
-			use_import_node ? document.importNode(node, true) : node.cloneNode(true)
+			use_import_node || is_firefox ? document.importNode(node, true) : node.cloneNode(true)
 		);
 
 		if (is_fragment) {
diff --git a/packages/svelte/src/internal/client/index.js b/packages/svelte/src/internal/client/index.js
index 2f32e8c25b..4f74408b7a 100644
--- a/packages/svelte/src/internal/client/index.js
+++ b/packages/svelte/src/internal/client/index.js
@@ -10,6 +10,7 @@ export {
 	mark_module_start,
 	mark_module_end,
 	add_owner_effect,
+	add_owner_to_class,
 	skip_ownership_validation
 } from './dev/ownership.js';
 export { check_target, legacy_api } from './dev/legacy.js';
@@ -35,7 +36,6 @@ export {
 	set_attributes,
 	set_custom_element_data,
 	set_xlink_attribute,
-	handle_lazy_img,
 	set_value,
 	set_checked,
 	set_selected,
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index 946d9d9bdc..0b9d22fa56 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -51,6 +51,7 @@ import {
 } from './context.js';
 import { Boundary } from './dom/blocks/boundary.js';
 import * as w from './warnings.js';
+import { is_firefox } from './dom/operations.js';
 
 const FLUSH_MICROTASK = 0;
 const FLUSH_SYNC = 1;
@@ -352,7 +353,7 @@ export function handle_error(error, effect, previous_effect, component_context)
 		current_context = current_context.p;
 	}
 
-	const indent = /Firefox/.test(navigator.userAgent) ? '  ' : '\t';
+	const indent = is_firefox ? '  ' : '\t';
 	define_property(error, 'message', {
 		value: error.message + `\n${component_stack.map((name) => `\n${indent}in ${name}`).join('')}\n`
 	});
@@ -388,22 +389,18 @@ export function handle_error(error, effect, previous_effect, component_context)
 /**
  * @param {Value} signal
  * @param {Effect} effect
- * @param {number} [depth]
+ * @param {boolean} [root]
  */
-function schedule_possible_effect_self_invalidation(signal, effect, depth = 0) {
+function schedule_possible_effect_self_invalidation(signal, effect, root = true) {
 	var reactions = signal.reactions;
 	if (reactions === null) return;
 
 	for (var i = 0; i < reactions.length; i++) {
 		var reaction = reactions[i];
 		if ((reaction.f & DERIVED) !== 0) {
-			schedule_possible_effect_self_invalidation(
-				/** @type {Derived} */ (reaction),
-				effect,
-				depth + 1
-			);
+			schedule_possible_effect_self_invalidation(/** @type {Derived} */ (reaction), effect, false);
 		} else if (effect === reaction) {
-			if (depth === 0) {
+			if (root) {
 				set_signal_status(reaction, DIRTY);
 			} else if ((reaction.f & CLEAN) !== 0) {
 				set_signal_status(reaction, MAYBE_DIRTY);
@@ -477,6 +474,8 @@ export function update_reaction(reaction) {
 		if (
 			is_runes() &&
 			untracked_writes !== null &&
+			!untracking &&
+			deps !== null &&
 			(reaction.f & (DERIVED | MAYBE_DIRTY | DIRTY)) === 0
 		) {
 			for (i = 0; i < /** @type {Source[]} */ (untracked_writes).length; i++) {
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index ada6f9019d..b246076156 100644
--- a/packages/svelte/src/version.js
+++ b/packages/svelte/src/version.js
@@ -4,5 +4,5 @@
  * The current version, as set in package.json.
  * @type {string}
  */
-export const VERSION = '5.19.10';
+export const VERSION = '5.20.0';
 export const PUBLIC_VERSION = '5';
diff --git a/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/_config.js b/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/_config.js
new file mode 100644
index 0000000000..ab94125503
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/_config.js
@@ -0,0 +1,33 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ target, assert }) {
+		// Test for https://github.com/sveltejs/svelte/issues/15237
+		const [setValues, clearValue] = target.querySelectorAll('button');
+		const [text1, text2, check1, check2] = target.querySelectorAll('input');
+
+		assert.equal(text1.value, '');
+		assert.equal(text2.value, '');
+		assert.equal(check1.checked, false);
+		assert.equal(check2.checked, false);
+
+		flushSync(() => {
+			setValues.click();
+		});
+
+		assert.equal(text1.value, 'message');
+		assert.equal(text2.value, 'message');
+		assert.equal(check1.checked, true);
+		assert.equal(check2.checked, true);
+
+		flushSync(() => {
+			clearValue.click();
+		});
+
+		assert.equal(text1.value, '');
+		assert.equal(text2.value, '');
+		assert.equal(check1.checked, false);
+		assert.equal(check2.checked, false);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/main.svelte b/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/main.svelte
new file mode 100644
index 0000000000..4bb4365ee2
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/attribute-spread-input/main.svelte
@@ -0,0 +1,22 @@
+<script>
+	let value = $state();
+	let checked = $state(false);
+
+	function setValues() {
+		value = 'message';
+		checked = true;
+	}
+	function clearValues() {
+		value = null;
+		checked = null;
+	}
+</script>
+
+<button onclick={setValues}>setValues</button>
+<button onclick={clearValues}>clearValues</button>
+
+<input type="text" {value} />
+<input type="text" {value} {...{}} />
+
+<input type="checkbox" {checked} />
+<input type="checkbox" {checked} {...{}} />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte
new file mode 100644
index 0000000000..d6da559fb1
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte
@@ -0,0 +1,7 @@
+<script>
+	let { linked3 = $bindable(), linked4 = $bindable() } = $props();
+</script>
+
+<p>Binding</p>
+<button onclick={() => linked3.count++}>Increment Linked 1 ({linked3.count})</button>
+<button onclick={() => linked4.count++}>Increment Linked 2 ({linked4.count})</button>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte
new file mode 100644
index 0000000000..b935f0a472
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte
@@ -0,0 +1,13 @@
+<script>
+	import { getContext } from 'svelte';
+	const linked1 = getContext('linked1');
+	const linked2 = getContext('linked2');
+</script>
+
+<p>Context</p>
+<button onclick={() => linked1.linked.current.count++}
+	>Increment Linked 1 ({linked1.linked.current.count})</button
+>
+<button onclick={() => linked2.linked.current.count++}
+	>Increment Linked 2 ({linked2.linked.current.count})</button
+>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js
new file mode 100644
index 0000000000..d6d12d01cd
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js
@@ -0,0 +1,34 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+// Tests that ownership is widened with $derived (on class or on its own) that contains $state
+export default test({
+	compileOptions: {
+		dev: true
+	},
+
+	test({ assert, target, warnings }) {
+		const [root, counter_context1, counter_context2, counter_binding1, counter_binding2] =
+			target.querySelectorAll('button');
+
+		counter_context1.click();
+		counter_context2.click();
+		counter_binding1.click();
+		counter_binding2.click();
+		flushSync();
+
+		assert.equal(warnings.length, 0);
+
+		root.click();
+		flushSync();
+		counter_context1.click();
+		counter_context2.click();
+		counter_binding1.click();
+		counter_binding2.click();
+		flushSync();
+
+		assert.equal(warnings.length, 0);
+	},
+
+	warnings: []
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte
new file mode 100644
index 0000000000..aaade26e16
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte
@@ -0,0 +1,46 @@
+<script>
+	import CounterBinding from './CounterBinding.svelte';
+	import CounterContext from './CounterContext.svelte';
+	import { setContext } from 'svelte';
+
+	let counter = $state({ count: 0 });
+
+	class Linked {
+		#getter;
+		linked = $derived.by(() => {
+			const state = $state({ current: $state.snapshot(this.#getter()) });
+			return state;
+		});
+
+		constructor(fn) {
+			this.#getter = fn;
+		}
+	}
+
+	const linked1 = $derived.by(() => {
+		const state = $state({ current: $state.snapshot(counter) });
+		return state;
+	});
+	const linked2 = new Linked(() => counter);
+
+	setContext('linked1', {
+		get linked() {
+			return linked1;
+		}
+	});
+	setContext('linked2', linked2);
+
+	const linked3 = $derived.by(() => {
+		const state = $state({ current: $state.snapshot(counter) });
+		return state;
+	});
+	const linked4 = new Linked(() => counter);
+</script>
+
+<p>Parent</p>
+<button onclick={() => counter.count++}>
+	Increment Original ({counter.count})
+</button>
+
+<CounterContext />
+<CounterBinding bind:linked3={linked3.current} bind:linked4={linked4.linked.current} />
diff --git a/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte b/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
index cd23b31096..e2942b21f3 100644
--- a/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
@@ -22,6 +22,11 @@
 
 	class MyClass implements Hello {}
 
+	abstract class MyAbstractClass {
+		abstract x(): void;
+		y() {}
+	}
+
 	declare const declared_const: number;
 	declare function declared_fn(): void;
 	declare class declared_class {
diff --git a/packages/svelte/tests/snapshot/samples/skip-static-subtree/_expected/client/index.svelte.js b/packages/svelte/tests/snapshot/samples/skip-static-subtree/_expected/client/index.svelte.js
index d0a7a01528..0e8d859c7e 100644
--- a/packages/svelte/tests/snapshot/samples/skip-static-subtree/_expected/client/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/skip-static-subtree/_expected/client/index.svelte.js
@@ -42,12 +42,8 @@ export default function Skip_static_subtree($$anchor, $$props) {
 	$.reset(select);
 
 	var img = $.sibling(select, 2);
-	var div_2 = $.sibling(img, 2);
-	var img_1 = $.child(div_2);
 
-	$.reset(div_2);
+	$.next(2);
 	$.template_effect(() => $.set_text(text, $$props.title));
-	$.handle_lazy_img(img);
-	$.handle_lazy_img(img_1);
 	$.append($$anchor, fragment);
 }
\ No newline at end of file
diff --git a/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/errors.json b/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/errors.json
new file mode 100644
index 0000000000..fe51488c70
--- /dev/null
+++ b/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/errors.json
@@ -0,0 +1 @@
+[]
diff --git a/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/input.svelte b/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/input.svelte
new file mode 100644
index 0000000000..92f3564920
--- /dev/null
+++ b/packages/svelte/tests/validator/samples/reassign-derived-private-public-field/input.svelte
@@ -0,0 +1,13 @@
+<script>
+	class Test {
+	  #deps = () => [];
+	
+	  deps = $derived.by(() => {
+		return [];
+	  });		
+			
+	  constructor(f = () => []) {
+		this.#deps = f;
+	  }
+	}
+  </script>
\ No newline at end of file