CVE-2026-66317 Microsoft Edge (Chromium-based) Tampering Vulnerability

Medium 5.4 Published Updated

An origin validation error in Microsoft Edge allows attackers to tamper with data over the network, requiring a patch.

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-2026-66317?

CVE-2026-66317 is a medium-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 perform tampering over a network.

Weakness: CWE-346

Which versions are affected by CVE-2026-66317?

It affects 1 product.

Products include Microsoft Edge Chromium.

How do I fix CVE-2026-66317?

No fix has been published for CVE-2026-66317 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-66317 being exploited?

There is no known exploitation of CVE-2026-66317 in the wild and no public exploit code.

All Microsoft Edge Chromium vulnerabilities

Sources

Also known as GHSA-xj82-8xpc-8x9g.

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