diff --git a/internal/storage/driver/copy.go b/internal/storage/driver/copy.go
new file mode 100644
index 000000000..1aa965be1
--- /dev/null
+++ b/internal/storage/driver/copy.go
@@ -0,0 +1,223 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package driver
+
+import (
+	"bytes"
+	"maps"
+	"slices"
+
+	"k8s.io/apimachinery/pkg/runtime"
+
+	chart "helm.sh/helm/v4/internal/chart/v3"
+	rspb "helm.sh/helm/v4/internal/release/v2"
+	"helm.sh/helm/v4/pkg/chart/common"
+)
+
+// copyRelease returns a deep copy of rls.
+//
+// The persistent drivers serialize releases on write and deserialize them on
+// read, so callers can never reach the stored data. The memory driver keeps
+// releases as Go values, and therefore has to copy them explicitly to offer the
+// same isolation.
+//
+// Values held in the release that Helm does not model, such as custom types
+// stored in Config, are copied as interface values rather than recursively.
+func copyRelease(rls *rspb.Release) *rspb.Release {
+	if rls == nil {
+		return nil
+	}
+	return &rspb.Release{
+		Name:        rls.Name,
+		Info:        copyInfo(rls.Info),
+		Chart:       copyChart(rls.Chart),
+		Config:      copyValues(rls.Config),
+		Manifest:    rls.Manifest,
+		Hooks:       copyHooks(rls.Hooks),
+		Version:     rls.Version,
+		Namespace:   rls.Namespace,
+		Labels:      maps.Clone(rls.Labels),
+		ApplyMethod: rls.ApplyMethod,
+	}
+}
+
+func copyInfo(info *rspb.Info) *rspb.Info {
+	if info == nil {
+		return nil
+	}
+	out := *info
+	if info.Resources != nil {
+		out.Resources = make(map[string][]runtime.Object, len(info.Resources))
+		for name, objs := range info.Resources {
+			copied := make([]runtime.Object, len(objs))
+			for i, obj := range objs {
+				if obj != nil {
+					copied[i] = obj.DeepCopyObject()
+				}
+			}
+			out.Resources[name] = copied
+		}
+	}
+	return &out
+}
+
+func copyHooks(hooks []*rspb.Hook) []*rspb.Hook {
+	if hooks == nil {
+		return nil
+	}
+	out := make([]*rspb.Hook, len(hooks))
+	for i, hook := range hooks {
+		if hook == nil {
+			continue
+		}
+		copied := *hook
+		copied.Events = slices.Clone(hook.Events)
+		copied.DeletePolicies = slices.Clone(hook.DeletePolicies)
+		copied.OutputLogPolicies = slices.Clone(hook.OutputLogPolicies)
+		out[i] = &copied
+	}
+	return out
+}
+
+func copyChart(ch *chart.Chart) *chart.Chart {
+	if ch == nil {
+		return nil
+	}
+	out := &chart.Chart{
+		Raw:           copyFiles(ch.Raw),
+		Metadata:      copyMetadata(ch.Metadata),
+		Lock:          copyLock(ch.Lock),
+		Templates:     copyFiles(ch.Templates),
+		Values:        copyValues(ch.Values),
+		Schema:        bytes.Clone(ch.Schema),
+		SchemaModTime: ch.SchemaModTime,
+		Files:         copyFiles(ch.Files),
+		ModTime:       ch.ModTime,
+	}
+	// AddDependency sets the parent of each dependency, which rebuilds the
+	// chart tree without reaching into the unexported fields.
+	for _, dep := range ch.Dependencies() {
+		out.AddDependency(copyChart(dep))
+	}
+	return out
+}
+
+func copyMetadata(md *chart.Metadata) *chart.Metadata {
+	if md == nil {
+		return nil
+	}
+	out := *md
+	out.Sources = slices.Clone(md.Sources)
+	out.Keywords = slices.Clone(md.Keywords)
+	out.Annotations = maps.Clone(md.Annotations)
+	if md.Maintainers != nil {
+		out.Maintainers = make([]*chart.Maintainer, len(md.Maintainers))
+		for i, m := range md.Maintainers {
+			if m == nil {
+				continue
+			}
+			copied := *m
+			out.Maintainers[i] = &copied
+		}
+	}
+	out.Dependencies = copyDependencies(md.Dependencies)
+	return &out
+}
+
+func copyLock(lock *chart.Lock) *chart.Lock {
+	if lock == nil {
+		return nil
+	}
+	out := *lock
+	out.Dependencies = copyDependencies(lock.Dependencies)
+	return &out
+}
+
+func copyDependencies(deps []*chart.Dependency) []*chart.Dependency {
+	if deps == nil {
+		return nil
+	}
+	out := make([]*chart.Dependency, len(deps))
+	for i, dep := range deps {
+		if dep == nil {
+			continue
+		}
+		copied := *dep
+		copied.Tags = slices.Clone(dep.Tags)
+		copied.ImportValues = copyValueSlice(dep.ImportValues)
+		out[i] = &copied
+	}
+	return out
+}
+
+func copyFiles(files []*common.File) []*common.File {
+	if files == nil {
+		return nil
+	}
+	out := make([]*common.File, len(files))
+	for i, file := range files {
+		if file == nil {
+			continue
+		}
+		copied := *file
+		copied.Data = bytes.Clone(file.Data)
+		out[i] = &copied
+	}
+	return out
+}
+
+// copyValues deep copies the maps and slices that make up decoded chart values
+// and release config. Other values are copied as interface values, which is
+// enough for the scalars these maps normally hold.
+func copyValues(values map[string]any) map[string]any {
+	if values == nil {
+		return nil
+	}
+	out := make(map[string]any, len(values))
+	for key, value := range values {
+		out[key] = copyValue(value)
+	}
+	return out
+}
+
+func copyValue(value any) any {
+	switch typed := value.(type) {
+	case map[string]any:
+		return copyValues(typed)
+	case map[any]any:
+		out := make(map[any]any, len(typed))
+		for key, nested := range typed {
+			out[key] = copyValue(nested)
+		}
+		return out
+	case []any:
+		return copyValueSlice(typed)
+	default:
+		return value
+	}
+}
+
+func copyValueSlice(values []any) []any {
+	if values == nil {
+		return nil
+	}
+	out := make([]any, len(values))
+	for i, value := range values {
+		out[i] = copyValue(value)
+	}
+	return out
+}
diff --git a/internal/storage/driver/copy_test.go b/internal/storage/driver/copy_test.go
new file mode 100644
index 000000000..fb4e64eac
--- /dev/null
+++ b/internal/storage/driver/copy_test.go
@@ -0,0 +1,114 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package driver
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	chart "helm.sh/helm/v4/internal/chart/v3"
+	rspb "helm.sh/helm/v4/internal/release/v2"
+	"helm.sh/helm/v4/pkg/chart/common"
+	rcommon "helm.sh/helm/v4/pkg/release/common"
+)
+
+// chartFixture builds a chart with a dependency, raw files and nested values so
+// the copy can be checked against the parts a JSON round-trip would drop.
+func chartFixture() *chart.Chart {
+	ch := &chart.Chart{
+		Metadata: &chart.Metadata{
+			Name:        "parent",
+			Annotations: map[string]string{"example.com/team": "helm"},
+			Maintainers: []*chart.Maintainer{{Name: "maintainer"}},
+		},
+		Raw:       []*common.File{{Name: "Chart.yaml", Data: []byte("name: parent")}},
+		Templates: []*common.File{{Name: "templates/cm.yaml", Data: []byte("kind: ConfigMap")}},
+		Values:    map[string]any{"nested": map[string]any{"replicas": 1}},
+		Schema:    []byte("schema-bytes"),
+	}
+	ch.AddDependency(&chart.Chart{Metadata: &chart.Metadata{Name: "child"}})
+	return ch
+}
+
+func releaseFixture() *rspb.Release {
+	rls := releaseStub("copy-me", 1, "default", rcommon.StatusDeployed)
+	rls.Chart = chartFixture()
+	rls.Config = map[string]any{"nested": map[string]any{"enabled": true}}
+	rls.Hooks = []*rspb.Hook{{
+		Name:   "pre-install",
+		Events: []rspb.HookEvent{rspb.HookPreInstall},
+	}}
+	return rls
+}
+
+func TestCopyReleaseIsIndependent(t *testing.T) {
+	rls := releaseFixture()
+	copied := copyRelease(rls)
+
+	require.NotSame(t, rls, copied)
+	assert.Equal(t, rls, copied, "a copy should hold the same data as the original")
+
+	copied.Info.Status = rcommon.StatusFailed
+	copied.Labels["key1"] = "changed"
+	copied.Config["nested"].(map[string]any)["enabled"] = false
+	copied.Chart.Metadata.Name = "renamed"
+	copied.Chart.Metadata.Annotations["example.com/team"] = "changed"
+	copied.Chart.Metadata.Maintainers[0].Name = "changed"
+	copied.Chart.Values["nested"].(map[string]any)["replicas"] = 2
+	copied.Chart.Raw[0].Data[0] = 'X'
+	copied.Chart.Schema[0] = 'X'
+	copied.Chart.Dependencies()[0].Metadata.Name = "changed"
+	copied.Hooks[0].Events[0] = rspb.HookPostInstall
+
+	assert.Equal(t, rcommon.StatusDeployed, rls.Info.Status)
+	assert.Equal(t, "val1", rls.Labels["key1"])
+	assert.Equal(t, true, rls.Config["nested"].(map[string]any)["enabled"])
+	assert.Equal(t, "parent", rls.Chart.Metadata.Name)
+	assert.Equal(t, "helm", rls.Chart.Metadata.Annotations["example.com/team"])
+	assert.Equal(t, "maintainer", rls.Chart.Metadata.Maintainers[0].Name)
+	assert.Equal(t, 1, rls.Chart.Values["nested"].(map[string]any)["replicas"])
+	assert.Equal(t, []byte("name: parent"), rls.Chart.Raw[0].Data)
+	assert.Equal(t, []byte("schema-bytes"), rls.Chart.Schema)
+	assert.Equal(t, "child", rls.Chart.Dependencies()[0].Metadata.Name)
+	assert.Equal(t, rspb.HookPreInstall, rls.Hooks[0].Events[0])
+}
+
+// The chart tree is rebuilt through AddDependency, so the copied dependency has
+// to point at the copied parent rather than the original one.
+func TestCopyReleaseRebuildsChartTree(t *testing.T) {
+	copied := copyRelease(releaseFixture())
+
+	require.Len(t, copied.Chart.Dependencies(), 1)
+	dep := copied.Chart.Dependencies()[0]
+	assert.Same(t, copied.Chart, dep.Parent())
+	assert.True(t, copied.Chart.IsRoot())
+	assert.Equal(t, "parent.child", dep.ChartPath())
+}
+
+func TestCopyReleaseKeepsNilFields(t *testing.T) {
+	copied := copyRelease(&rspb.Release{Name: "sparse"})
+
+	assert.Equal(t, "sparse", copied.Name)
+	assert.Nil(t, copied.Info)
+	assert.Nil(t, copied.Chart)
+	assert.Nil(t, copied.Config)
+	assert.Nil(t, copied.Hooks)
+	assert.Nil(t, copied.Labels)
+	assert.Nil(t, copyRelease(nil))
+}
diff --git a/internal/storage/driver/memory.go b/internal/storage/driver/memory.go
index 7ea4a014a..4e4746acf 100644
--- a/internal/storage/driver/memory.go
+++ b/internal/storage/driver/memory.go
@@ -79,7 +79,7 @@ func (mem *Memory) Get(key string) (release.Releaser, error) {
 		}
 		if recs, ok := mem.cache[mem.namespace][name]; ok {
 			if r := recs.Get(key); r != nil {
-				return r.rls, nil
+				return copyRelease(r.rls), nil
 			}
 		}
 		return nil, ErrReleaseNotFound
@@ -100,8 +100,11 @@ func (mem *Memory) List(filter func(release.Releaser) bool) ([]release.Releaser,
 		}
 		for _, recs := range mem.cache[namespace] {
 			recs.Iter(func(_ int, rec *record) bool {
-				if filter(rec.rls) {
-					ls = append(ls, rec.rls)
+				// Copy before filtering so the callback cannot reach the
+				// stored release either.
+				rls := copyRelease(rec.rls)
+				if filter(rls) {
+					ls = append(ls, rls)
 				}
 				return true
 			})
@@ -137,7 +140,7 @@ func (mem *Memory) Query(keyvals map[string]string) ([]release.Releaser, error)
 					return false
 				}
 				if rec.lbs.match(lbs) {
-					ls = append(ls, rec.rls)
+					ls = append(ls, copyRelease(rec.rls))
 				}
 				return true
 			})
diff --git a/internal/storage/driver/memory_test.go b/internal/storage/driver/memory_test.go
index 82f605e98..a41cd8f05 100644
--- a/internal/storage/driver/memory_test.go
+++ b/internal/storage/driver/memory_test.go
@@ -264,3 +264,82 @@ func TestMemoryDelete(t *testing.T) {
 		}
 	}
 }
+
+// A stored release should only change through Update, which is the contract the
+// persistent drivers already provide by encoding on write and decoding on read.
+func TestMemoryReleaseIsolation(t *testing.T) {
+	key := testKey("copy-me", 1)
+	tests := []struct {
+		desc   string
+		mutate func(t *testing.T, mem *Memory, rls *rspb.Release)
+	}{
+		{
+			desc: "create input",
+			mutate: func(_ *testing.T, _ *Memory, rls *rspb.Release) {
+				rls.Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "update input",
+			mutate: func(t *testing.T, mem *Memory, rls *rspb.Release) {
+				t.Helper()
+				require.NoError(t, mem.Update(key, rls))
+				rls.Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "get result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				rel, err := mem.Get(key)
+				require.NoError(t, err)
+				convertReleaserToV1(t, rel).Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "list result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				ls, err := mem.List(func(release.Releaser) bool { return true })
+				require.NoError(t, err)
+				require.Len(t, ls, 1)
+				convertReleaserToV1(t, ls[0]).Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "list filter argument",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				_, err := mem.List(func(rel release.Releaser) bool {
+					convertReleaserToV1(t, rel).Info.Status = common.StatusFailed
+					return false
+				})
+				require.NoError(t, err)
+			},
+		},
+		{
+			desc: "query result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				ls, err := mem.Query(map[string]string{"name": "copy-me"})
+				require.NoError(t, err)
+				require.Len(t, ls, 1)
+				convertReleaserToV1(t, ls[0]).Info.Status = common.StatusFailed
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			mem := NewMemory()
+			rls := releaseFixture()
+			require.NoError(t, mem.Create(key, rls))
+
+			tt.mutate(t, mem, rls)
+
+			stored, err := mem.Get(key)
+			require.NoError(t, err)
+			assert.Equal(t, common.StatusDeployed, convertReleaserToV1(t, stored).Info.Status)
+		})
+	}
+}
diff --git a/internal/storage/driver/records.go b/internal/storage/driver/records.go
index 14f13780d..0aca081a6 100644
--- a/internal/storage/driver/records.go
+++ b/internal/storage/driver/records.go
@@ -123,5 +123,7 @@ func newRecord(key string, rls *rspb.Release) *record {
 	lbs.set("status", rls.Info.Status.String())
 	lbs.set("version", strconv.Itoa(rls.Version))
 
-	return &record{key: key, lbs: lbs, rls: rls}
+	// Store a copy so later changes to the caller's release do not reach the
+	// record, matching the isolation the persistent drivers get from encoding.
+	return &record{key: key, lbs: lbs, rls: copyRelease(rls)}
 }
diff --git a/pkg/storage/driver/copy.go b/pkg/storage/driver/copy.go
new file mode 100644
index 000000000..6ee2c6514
--- /dev/null
+++ b/pkg/storage/driver/copy.go
@@ -0,0 +1,223 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package driver
+
+import (
+	"bytes"
+	"maps"
+	"slices"
+
+	"k8s.io/apimachinery/pkg/runtime"
+
+	"helm.sh/helm/v4/pkg/chart/common"
+	chart "helm.sh/helm/v4/pkg/chart/v2"
+	rspb "helm.sh/helm/v4/pkg/release/v1"
+)
+
+// copyRelease returns a deep copy of rls.
+//
+// The persistent drivers serialize releases on write and deserialize them on
+// read, so callers can never reach the stored data. The memory driver keeps
+// releases as Go values, and therefore has to copy them explicitly to offer the
+// same isolation.
+//
+// Values held in the release that Helm does not model, such as custom types
+// stored in Config, are copied as interface values rather than recursively.
+func copyRelease(rls *rspb.Release) *rspb.Release {
+	if rls == nil {
+		return nil
+	}
+	return &rspb.Release{
+		Name:        rls.Name,
+		Info:        copyInfo(rls.Info),
+		Chart:       copyChart(rls.Chart),
+		Config:      copyValues(rls.Config),
+		Manifest:    rls.Manifest,
+		Hooks:       copyHooks(rls.Hooks),
+		Version:     rls.Version,
+		Namespace:   rls.Namespace,
+		Labels:      maps.Clone(rls.Labels),
+		ApplyMethod: rls.ApplyMethod,
+	}
+}
+
+func copyInfo(info *rspb.Info) *rspb.Info {
+	if info == nil {
+		return nil
+	}
+	out := *info
+	if info.Resources != nil {
+		out.Resources = make(map[string][]runtime.Object, len(info.Resources))
+		for name, objs := range info.Resources {
+			copied := make([]runtime.Object, len(objs))
+			for i, obj := range objs {
+				if obj != nil {
+					copied[i] = obj.DeepCopyObject()
+				}
+			}
+			out.Resources[name] = copied
+		}
+	}
+	return &out
+}
+
+func copyHooks(hooks []*rspb.Hook) []*rspb.Hook {
+	if hooks == nil {
+		return nil
+	}
+	out := make([]*rspb.Hook, len(hooks))
+	for i, hook := range hooks {
+		if hook == nil {
+			continue
+		}
+		copied := *hook
+		copied.Events = slices.Clone(hook.Events)
+		copied.DeletePolicies = slices.Clone(hook.DeletePolicies)
+		copied.OutputLogPolicies = slices.Clone(hook.OutputLogPolicies)
+		out[i] = &copied
+	}
+	return out
+}
+
+func copyChart(ch *chart.Chart) *chart.Chart {
+	if ch == nil {
+		return nil
+	}
+	out := &chart.Chart{
+		Raw:           copyFiles(ch.Raw),
+		Metadata:      copyMetadata(ch.Metadata),
+		Lock:          copyLock(ch.Lock),
+		Templates:     copyFiles(ch.Templates),
+		Values:        copyValues(ch.Values),
+		Schema:        bytes.Clone(ch.Schema),
+		SchemaModTime: ch.SchemaModTime,
+		Files:         copyFiles(ch.Files),
+		ModTime:       ch.ModTime,
+	}
+	// AddDependency sets the parent of each dependency, which rebuilds the
+	// chart tree without reaching into the unexported fields.
+	for _, dep := range ch.Dependencies() {
+		out.AddDependency(copyChart(dep))
+	}
+	return out
+}
+
+func copyMetadata(md *chart.Metadata) *chart.Metadata {
+	if md == nil {
+		return nil
+	}
+	out := *md
+	out.Sources = slices.Clone(md.Sources)
+	out.Keywords = slices.Clone(md.Keywords)
+	out.Annotations = maps.Clone(md.Annotations)
+	if md.Maintainers != nil {
+		out.Maintainers = make([]*chart.Maintainer, len(md.Maintainers))
+		for i, m := range md.Maintainers {
+			if m == nil {
+				continue
+			}
+			copied := *m
+			out.Maintainers[i] = &copied
+		}
+	}
+	out.Dependencies = copyDependencies(md.Dependencies)
+	return &out
+}
+
+func copyLock(lock *chart.Lock) *chart.Lock {
+	if lock == nil {
+		return nil
+	}
+	out := *lock
+	out.Dependencies = copyDependencies(lock.Dependencies)
+	return &out
+}
+
+func copyDependencies(deps []*chart.Dependency) []*chart.Dependency {
+	if deps == nil {
+		return nil
+	}
+	out := make([]*chart.Dependency, len(deps))
+	for i, dep := range deps {
+		if dep == nil {
+			continue
+		}
+		copied := *dep
+		copied.Tags = slices.Clone(dep.Tags)
+		copied.ImportValues = copyValueSlice(dep.ImportValues)
+		out[i] = &copied
+	}
+	return out
+}
+
+func copyFiles(files []*common.File) []*common.File {
+	if files == nil {
+		return nil
+	}
+	out := make([]*common.File, len(files))
+	for i, file := range files {
+		if file == nil {
+			continue
+		}
+		copied := *file
+		copied.Data = bytes.Clone(file.Data)
+		out[i] = &copied
+	}
+	return out
+}
+
+// copyValues deep copies the maps and slices that make up decoded chart values
+// and release config. Other values are copied as interface values, which is
+// enough for the scalars these maps normally hold.
+func copyValues(values map[string]any) map[string]any {
+	if values == nil {
+		return nil
+	}
+	out := make(map[string]any, len(values))
+	for key, value := range values {
+		out[key] = copyValue(value)
+	}
+	return out
+}
+
+func copyValue(value any) any {
+	switch typed := value.(type) {
+	case map[string]any:
+		return copyValues(typed)
+	case map[any]any:
+		out := make(map[any]any, len(typed))
+		for key, nested := range typed {
+			out[key] = copyValue(nested)
+		}
+		return out
+	case []any:
+		return copyValueSlice(typed)
+	default:
+		return value
+	}
+}
+
+func copyValueSlice(values []any) []any {
+	if values == nil {
+		return nil
+	}
+	out := make([]any, len(values))
+	for i, value := range values {
+		out[i] = copyValue(value)
+	}
+	return out
+}
diff --git a/pkg/storage/driver/copy_test.go b/pkg/storage/driver/copy_test.go
new file mode 100644
index 000000000..aebaef08f
--- /dev/null
+++ b/pkg/storage/driver/copy_test.go
@@ -0,0 +1,114 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package driver
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"helm.sh/helm/v4/pkg/chart/common"
+	chart "helm.sh/helm/v4/pkg/chart/v2"
+	rcommon "helm.sh/helm/v4/pkg/release/common"
+	rspb "helm.sh/helm/v4/pkg/release/v1"
+)
+
+// chartFixture builds a chart with a dependency, raw files and nested values so
+// the copy can be checked against the parts a JSON round-trip would drop.
+func chartFixture() *chart.Chart {
+	ch := &chart.Chart{
+		Metadata: &chart.Metadata{
+			Name:        "parent",
+			Annotations: map[string]string{"example.com/team": "helm"},
+			Maintainers: []*chart.Maintainer{{Name: "maintainer"}},
+		},
+		Raw:       []*common.File{{Name: "Chart.yaml", Data: []byte("name: parent")}},
+		Templates: []*common.File{{Name: "templates/cm.yaml", Data: []byte("kind: ConfigMap")}},
+		Values:    map[string]any{"nested": map[string]any{"replicas": 1}},
+		Schema:    []byte("schema-bytes"),
+	}
+	ch.AddDependency(&chart.Chart{Metadata: &chart.Metadata{Name: "child"}})
+	return ch
+}
+
+func releaseFixture() *rspb.Release {
+	rls := releaseStub("copy-me", 1, "default", rcommon.StatusDeployed)
+	rls.Chart = chartFixture()
+	rls.Config = map[string]any{"nested": map[string]any{"enabled": true}}
+	rls.Hooks = []*rspb.Hook{{
+		Name:   "pre-install",
+		Events: []rspb.HookEvent{rspb.HookPreInstall},
+	}}
+	return rls
+}
+
+func TestCopyReleaseIsIndependent(t *testing.T) {
+	rls := releaseFixture()
+	copied := copyRelease(rls)
+
+	require.NotSame(t, rls, copied)
+	assert.Equal(t, rls, copied, "a copy should hold the same data as the original")
+
+	copied.Info.Status = rcommon.StatusFailed
+	copied.Labels["key1"] = "changed"
+	copied.Config["nested"].(map[string]any)["enabled"] = false
+	copied.Chart.Metadata.Name = "renamed"
+	copied.Chart.Metadata.Annotations["example.com/team"] = "changed"
+	copied.Chart.Metadata.Maintainers[0].Name = "changed"
+	copied.Chart.Values["nested"].(map[string]any)["replicas"] = 2
+	copied.Chart.Raw[0].Data[0] = 'X'
+	copied.Chart.Schema[0] = 'X'
+	copied.Chart.Dependencies()[0].Metadata.Name = "changed"
+	copied.Hooks[0].Events[0] = rspb.HookPostInstall
+
+	assert.Equal(t, rcommon.StatusDeployed, rls.Info.Status)
+	assert.Equal(t, "val1", rls.Labels["key1"])
+	assert.Equal(t, true, rls.Config["nested"].(map[string]any)["enabled"])
+	assert.Equal(t, "parent", rls.Chart.Metadata.Name)
+	assert.Equal(t, "helm", rls.Chart.Metadata.Annotations["example.com/team"])
+	assert.Equal(t, "maintainer", rls.Chart.Metadata.Maintainers[0].Name)
+	assert.Equal(t, 1, rls.Chart.Values["nested"].(map[string]any)["replicas"])
+	assert.Equal(t, []byte("name: parent"), rls.Chart.Raw[0].Data)
+	assert.Equal(t, []byte("schema-bytes"), rls.Chart.Schema)
+	assert.Equal(t, "child", rls.Chart.Dependencies()[0].Metadata.Name)
+	assert.Equal(t, rspb.HookPreInstall, rls.Hooks[0].Events[0])
+}
+
+// The chart tree is rebuilt through AddDependency, so the copied dependency has
+// to point at the copied parent rather than the original one.
+func TestCopyReleaseRebuildsChartTree(t *testing.T) {
+	copied := copyRelease(releaseFixture())
+
+	require.Len(t, copied.Chart.Dependencies(), 1)
+	dep := copied.Chart.Dependencies()[0]
+	assert.Same(t, copied.Chart, dep.Parent())
+	assert.True(t, copied.Chart.IsRoot())
+	assert.Equal(t, "parent.child", dep.ChartPath())
+}
+
+func TestCopyReleaseKeepsNilFields(t *testing.T) {
+	copied := copyRelease(&rspb.Release{Name: "sparse"})
+
+	assert.Equal(t, "sparse", copied.Name)
+	assert.Nil(t, copied.Info)
+	assert.Nil(t, copied.Chart)
+	assert.Nil(t, copied.Config)
+	assert.Nil(t, copied.Hooks)
+	assert.Nil(t, copied.Labels)
+	assert.Nil(t, copyRelease(nil))
+}
diff --git a/pkg/storage/driver/memory.go b/pkg/storage/driver/memory.go
index 7ea4a014a..4e4746acf 100644
--- a/pkg/storage/driver/memory.go
+++ b/pkg/storage/driver/memory.go
@@ -79,7 +79,7 @@ func (mem *Memory) Get(key string) (release.Releaser, error) {
 		}
 		if recs, ok := mem.cache[mem.namespace][name]; ok {
 			if r := recs.Get(key); r != nil {
-				return r.rls, nil
+				return copyRelease(r.rls), nil
 			}
 		}
 		return nil, ErrReleaseNotFound
@@ -100,8 +100,11 @@ func (mem *Memory) List(filter func(release.Releaser) bool) ([]release.Releaser,
 		}
 		for _, recs := range mem.cache[namespace] {
 			recs.Iter(func(_ int, rec *record) bool {
-				if filter(rec.rls) {
-					ls = append(ls, rec.rls)
+				// Copy before filtering so the callback cannot reach the
+				// stored release either.
+				rls := copyRelease(rec.rls)
+				if filter(rls) {
+					ls = append(ls, rls)
 				}
 				return true
 			})
@@ -137,7 +140,7 @@ func (mem *Memory) Query(keyvals map[string]string) ([]release.Releaser, error)
 					return false
 				}
 				if rec.lbs.match(lbs) {
-					ls = append(ls, rec.rls)
+					ls = append(ls, copyRelease(rec.rls))
 				}
 				return true
 			})
diff --git a/pkg/storage/driver/memory_test.go b/pkg/storage/driver/memory_test.go
index 745b12345..20cf37058 100644
--- a/pkg/storage/driver/memory_test.go
+++ b/pkg/storage/driver/memory_test.go
@@ -264,3 +264,82 @@ func TestMemoryDelete(t *testing.T) {
 		}
 	}
 }
+
+// A stored release should only change through Update, which is the contract the
+// persistent drivers already provide by encoding on write and decoding on read.
+func TestMemoryReleaseIsolation(t *testing.T) {
+	key := testKey("copy-me", 1)
+	tests := []struct {
+		desc   string
+		mutate func(t *testing.T, mem *Memory, rls *rspb.Release)
+	}{
+		{
+			desc: "create input",
+			mutate: func(_ *testing.T, _ *Memory, rls *rspb.Release) {
+				rls.Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "update input",
+			mutate: func(t *testing.T, mem *Memory, rls *rspb.Release) {
+				t.Helper()
+				require.NoError(t, mem.Update(key, rls))
+				rls.Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "get result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				rel, err := mem.Get(key)
+				require.NoError(t, err)
+				convertReleaserToV1(t, rel).Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "list result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				ls, err := mem.List(func(release.Releaser) bool { return true })
+				require.NoError(t, err)
+				require.Len(t, ls, 1)
+				convertReleaserToV1(t, ls[0]).Info.Status = common.StatusFailed
+			},
+		},
+		{
+			desc: "list filter argument",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				_, err := mem.List(func(rel release.Releaser) bool {
+					convertReleaserToV1(t, rel).Info.Status = common.StatusFailed
+					return false
+				})
+				require.NoError(t, err)
+			},
+		},
+		{
+			desc: "query result",
+			mutate: func(t *testing.T, mem *Memory, _ *rspb.Release) {
+				t.Helper()
+				ls, err := mem.Query(map[string]string{"name": "copy-me"})
+				require.NoError(t, err)
+				require.Len(t, ls, 1)
+				convertReleaserToV1(t, ls[0]).Info.Status = common.StatusFailed
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			mem := NewMemory()
+			rls := releaseFixture()
+			require.NoError(t, mem.Create(key, rls))
+
+			tt.mutate(t, mem, rls)
+
+			stored, err := mem.Get(key)
+			require.NoError(t, err)
+			assert.Equal(t, common.StatusDeployed, convertReleaserToV1(t, stored).Info.Status)
+		})
+	}
+}
diff --git a/pkg/storage/driver/records.go b/pkg/storage/driver/records.go
index 3393bb603..8c2b0594f 100644
--- a/pkg/storage/driver/records.go
+++ b/pkg/storage/driver/records.go
@@ -123,6 +123,7 @@ func newRecord(key string, rls *rspb.Release) *record {
 	lbs.set("status", rls.Info.Status.String())
 	lbs.set("version", strconv.Itoa(rls.Version))
 
-	// return &record{key: key, lbs: lbs, rls: proto.Clone(rls).(*rspb.Release)}
-	return &record{key: key, lbs: lbs, rls: rls}
+	// Store a copy so later changes to the caller's release do not reach the
+	// record, matching the isolation the persistent drivers get from encoding.
+	return &record{key: key, lbs: lbs, rls: copyRelease(rls)}
 }