CVE-2026-66318 Microsoft Edge (Chromium-based) Information Disclosure Vulnerability

High 8.1 Published Updated

An origin validation error in Microsoft Edge allows attackers to disclose sensitive information over the network.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-66318?

CVE-2026-66318 is a high-severity vulnerability in Microsoft Edge Chromium, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose information over a network.

Weakness: CWE-346

Which versions are affected by CVE-2026-66318?

It affects 1 product.

Products include Microsoft Edge Chromium.

How do I fix CVE-2026-66318?

No fix has been published for CVE-2026-66318 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-66318 being exploited?

There is no known exploitation of CVE-2026-66318 in the wild and no public exploit code.

All Microsoft Edge Chromium vulnerabilities

Sources

Also known as GHSA-wx3x-ccqc-xq62.

Is CVE-2026-66318 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free