CVE-2026-78959 Security feature bypass in Chrome

Medium 6.5 Published Updated

Remote attackers can bypass system access restrictions via crafted HTML pages due to improper case sensitivity handling in the FileSystem API.

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
Available

What is CVE-2026-78959?

CVE-2026-78959 is a medium-severity vulnerability in Google Chrome, published on 25 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

Improper handling of case sensitivity in FileSystem in Google Chrome prior to 152.0.7977.65 allowed a remote attacker leveraging social engineering to bypass system access restrictions via a crafted HTML page. (Chromium security severity: Medium)

Weakness: CWE-178

Which versions are affected by CVE-2026-78959?

It affects 1 product.

Products include Google Chrome.

How do I fix CVE-2026-78959?

Upgrade to a fixed version.

Is CVE-2026-78959 being exploited?

There is no known exploitation of CVE-2026-78959 in the wild and no public exploit code.

All Google Chrome vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-78959, ECHO-dd5e-c98c-080f, GHSA-35mw-8r7p-2p48, MINI-wgw5-q4rm-p98h.

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