In plain language
What this advisory means
A security issue known as CVE-2026-76021 involves a "use after free" bug in the Document Object Model (DOM) of the Chromium browser engine. Microsoft Edge, which uses Chromium, has incorporated a Chromium update that fixes this problem. Users should update Microsoft Edge to version 151.0.4129.107 or later to be protected.
Technical explanation
How the issue affects the environment
The vulnerability CVE-2026-76021 is a use-after-free flaw in the DOM implementation of the Chromium browser engine. This occurs when a program continues to reference memory after it has been freed, potentially allowing an attacker to execute arbitrary code or cause a crash. Microsoft Edge, built on the Chromium engine, has ingested the Chromium patch that addresses this issue. Updating to Microsoft Edge version 151.0.4129.107, which includes Chromium version 151.0.7922.174 or later, mitigates this vulnerability.
Operational impact
Why teams should care
If unaddressed, this vulnerability could allow attackers to execute code within the context of the browser, potentially compromising user data and system security. Organizations relying on Microsoft Edge should update to the fixed version to maintain secure browsing and protect sensitive information.
Immediate action
Update Microsoft Edge (Chromium-based) to version 151.0.4129.107 or later, which includes the Chromium update that fixes this use-after-free vulnerability in the DOM.
Affected and fixed releases
Temporary risk reduction
No separate workaround was supplied in the source feed. Use the official vendor advisory before changing production controls.
Evidence and validation checklist
- Microsoft Security Response Center advisory confirming ingestion of Chromium patch for CVE-2026-76021.
- Microsoft Edge version 151.0.4129.107 incorporating the Chromium fix.
- Reference to Chrome Releases for more detail on the update.
- Security Update Guide entry outlining update details.
Authoritative reference
Microsoft Security Response Center
QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.