diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index a2c197c5a8..bc972208ff 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "hyperframes",
   "description": "HyperFrames by HeyGen. Write HTML, render video. Compositions, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com",
diff --git a/.codex-plugin/plugin.json b/.codex-plugin/plugin.json
index eedd94f364..4a133b8dfa 100644
--- a/.codex-plugin/plugin.json
+++ b/.codex-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "hyperframes",
   "description": "Write HTML, render video. Compositions, Tailwind v4 styles, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com",
diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json
index af510dc3a7..fd5bf7fbd6 100644
--- a/.cursor-plugin/plugin.json
+++ b/.cursor-plugin/plugin.json
@@ -3,7 +3,7 @@
   "name": "hyperframes",
   "displayName": "HyperFrames by HeyGen",
   "description": "Write HTML, render video. Compositions, Tailwind v4 styles, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com"
diff --git a/docs/changelog.mdx b/docs/changelog.mdx
index dc0f4086da..0032301b2d 100644
--- a/docs/changelog.mdx
+++ b/docs/changelog.mdx
@@ -8,6 +8,20 @@ Recent HyperFrames releases, including user-facing features, fixes, and migratio
 
 {/* New release entries are prepended by `bun run changelog:draft <version> --write`. */}
 
+<Update
+  label="HyperFrames v0.8.40"
+  description="Released - 2026-09-14"
+  tags={["Release", "Core"]}
+>
+Sandboxed compositions no longer lose audio while the timeline and visuals keep playing.
+
+## Fixes
+
+- **Core:** Web Audio routing now checks the document’s security origin with `window.origin`. Media without `crossorigin` stays out of Web Audio when that origin is opaque, even if the URL origins match ([293829a2c](https://github.com/heygen-com/hyperframes/commit/293829a2c1bde0707548b230b74b5cdf8e8985f2), [#3937](https://github.com/heygen-com/hyperframes/pull/3937)).
+
+[View the full commit range](https://github.com/heygen-com/hyperframes/compare/v0.8.39...v0.8.40).
+</Update>
+
 <Update
   label="HyperFrames v0.8.39"
   description="Released - 2026-09-14"
diff --git a/packages/aws-lambda/package.json b/packages/aws-lambda/package.json
index 2d3d925630..315acb94b5 100644
--- a/packages/aws-lambda/package.json
+++ b/packages/aws-lambda/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/aws-lambda",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "AWS Lambda adapter for HyperFrames distributed rendering — handler, client-side SDK, and CDK construct.",
   "repository": {
     "type": "git",
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 84ce551035..08972816b2 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/cli",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "HyperFrames CLI — create, preview, and render HTML video compositions",
   "license": "Apache-2.0",
   "repository": {
diff --git a/packages/core/package.json b/packages/core/package.json
index da592a16b4..6b31bfde08 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/core",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "",
   "repository": {
     "type": "git",
diff --git a/packages/engine/package.json b/packages/engine/package.json
index 7dd6fcb1b0..f4a97e9501 100644
--- a/packages/engine/package.json
+++ b/packages/engine/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/engine",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "Seekable web page to video rendering engine (Puppeteer + FFmpeg)",
   "repository": {
     "type": "git",
diff --git a/packages/gcp-cloud-run/package.json b/packages/gcp-cloud-run/package.json
index 189820d1e9..169b159394 100644
--- a/packages/gcp-cloud-run/package.json
+++ b/packages/gcp-cloud-run/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/gcp-cloud-run",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "Google Cloud Run + Workflows adapter for HyperFrames distributed rendering — request handler, client-side SDK, and Terraform module.",
   "repository": {
     "type": "git",
diff --git a/packages/lint/package.json b/packages/lint/package.json
index 25547a9f4a..c159529c1a 100644
--- a/packages/lint/package.json
+++ b/packages/lint/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/lint",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/parsers/package.json b/packages/parsers/package.json
index 916ed31bd7..14b324a893 100644
--- a/packages/parsers/package.json
+++ b/packages/parsers/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/parsers",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/player/package.json b/packages/player/package.json
index c8efbe30d7..f28c1a0581 100644
--- a/packages/player/package.json
+++ b/packages/player/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/player",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "Embeddable web component for HyperFrames compositions",
   "repository": {
     "type": "git",
diff --git a/packages/producer/package.json b/packages/producer/package.json
index b1f6ee1ed3..53c33d4108 100644
--- a/packages/producer/package.json
+++ b/packages/producer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/producer",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "HTML-to-video rendering engine using Chrome's BeginFrame API",
   "repository": {
     "type": "git",
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 7fa24a20e2..abe685199d 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/sdk",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "Headless, framework-neutral HyperFrames composition editing engine",
   "repository": {
     "type": "git",
diff --git a/packages/shader-transitions/package.json b/packages/shader-transitions/package.json
index 691a4c71ee..659a9213c1 100644
--- a/packages/shader-transitions/package.json
+++ b/packages/shader-transitions/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/shader-transitions",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "WebGL shader transitions for HyperFrames compositions",
   "repository": {
     "type": "git",
diff --git a/packages/studio-server/package.json b/packages/studio-server/package.json
index 0cd7ab1043..cc927af1b3 100644
--- a/packages/studio-server/package.json
+++ b/packages/studio-server/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/studio-server",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/studio/package.json b/packages/studio/package.json
index 28fd777b39..29beffc03c 100644
--- a/packages/studio/package.json
+++ b/packages/studio/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/studio",
-  "version": "0.8.39",
+  "version": "0.8.40",
   "description": "",
   "repository": {
     "type": "git",
diff --git a/releases/v0.8.40.md b/releases/v0.8.40.md
new file mode 100644
index 0000000000..31d79b7968
--- /dev/null
+++ b/releases/v0.8.40.md
@@ -0,0 +1,13 @@
+# HyperFrames v0.8.40
+
+Released on 2026-09-14.
+
+Sandboxed compositions no longer lose audio while the timeline and visuals keep playing.
+
+## Fixes
+
+- **Core:** Web Audio routing now checks the document’s security origin with `window.origin`. Media without `crossorigin` stays out of Web Audio when that origin is opaque, even if the URL origins match ([293829a2c](https://github.com/heygen-com/hyperframes/commit/293829a2c1bde0707548b230b74b5cdf8e8985f2), [#3937](https://github.com/heygen-com/hyperframes/pull/3937)).
+
+## Full changelog
+
+https://github.com/heygen-com/hyperframes/compare/v0.8.39...v0.8.40