CVE-2026-78376 Webkitgtk: use-after-free of jscvalue function parameters

High 8.8 Published Updated

Attackers can execute arbitrary code by exploiting a use-after-free vulnerability in WebKitGTK when processing malicious web content.

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-2026-78376?

CVE-2026-78376 is a high-severity use after free vulnerability in Red Hat Enterprise Linux 6, published on 24 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

A flaw was found in WebKitGTK. Processing malicious web content can cause a use-after-free issue due to improper memory handling and result in memory corruption.

Weakness: CWE-416

Which versions are affected by CVE-2026-78376?

How do I fix CVE-2026-78376?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-78376 being exploited?

There is no known exploitation of CVE-2026-78376 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2026-78376, ECHO-1c9d-3961-cc2b, GHSA-qcc7-6r53-qpph, UBUNTU-CVE-2026-78376.

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