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fix: Harden extension host iframe message origin validation #280

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Merged
skazantsev merged 1 commit into from
Jul 9, 2026
+11 −8
Merged

fix: Harden extension host iframe message origin validation #280

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19 changes: 11 additions & 8 deletions patches/web-server/webview.diff
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Original file line number Diff line number Diff line change
Expand Up @@ -86,17 +86,20 @@ Index: code-editor-src/src/vs/workbench/services/extensions/worker/webWorkerExte
===================================================================
--- code-editor-src.orig/src/vs/workbench/services/extensions/worker/webWorkerExtensionHostIframe.html
+++ code-editor-src/src/vs/workbench/services/extensions/worker/webWorkerExtensionHostIframe.html
@@ -25,6 +25,13 @@
// validation not requested
@@ -15,7 +15,7 @@
// DO NOT CHANGE the name of the worker without also updating js-debug, as that
// is used to filter targets to attach to (e.g. #232544)
const name = searchParams.get('debugged') ? 'DebugExtensionHostWorker' : 'ExtensionHostWorker';
- const parentOrigin = searchParams.get('parentOrigin') || window.origin;
+ let parentOrigin = window.origin;
const salt = searchParams.get('salt');

(async function () {
@@ -25,6 +25,8 @@
return start();
}
+
+ // It is safe to run if we are on the same host.
+ const parent = new URL(parentOrigin)
+ if (parent.hostname === hostname) {
+ return start()
+ }
+
+ parentOrigin = searchParams.get('parentOrigin') || window.origin;
if (!crypto.subtle) {
// cannot validate, not running in a secure context
return sendError(new Error(`Cannot validate in current context!`));