diff --git a/.changeset/late-geckos-draw.md b/.changeset/late-geckos-draw.md
new file mode 100644
index 0000000000..93c4fffc1d
--- /dev/null
+++ b/.changeset/late-geckos-draw.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: try catch `strict_equals` to avoid error accessing `STATE_SYMBOL`
diff --git a/packages/svelte/src/internal/client/dev/equality.js b/packages/svelte/src/internal/client/dev/equality.js
index c1c392ba87..170f7baf95 100644
--- a/packages/svelte/src/internal/client/dev/equality.js
+++ b/packages/svelte/src/internal/client/dev/equality.js
@@ -78,9 +78,13 @@ export function init_array_prototype_warnings() {
  * @returns {boolean}
  */
 export function strict_equals(a, b, equal = true) {
-	if ((a === b) !== (get_proxied_value(a) === get_proxied_value(b))) {
-		w.state_proxy_equality_mismatch(equal ? '===' : '!==');
-	}
+	// try-catch needed because this tries to read properties of `a` and `b`,
+	// which could be disallowed for example in a secure context
+	try {
+		if ((a === b) !== (get_proxied_value(a) === get_proxied_value(b))) {
+			w.state_proxy_equality_mismatch(equal ? '===' : '!==');
+		}
+	} catch {}
 
 	return (a === b) === equal;
 }