CVE-2026-96423 Heap-based Buffer Overflow in Wireshark

Medium 5.5 Published Updated

A heap-based buffer overflow in the X11 protocol dissector allows attackers to cause a denial of service in Wireshark.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-96423?

CVE-2026-96423 is a medium-severity memory corruption vulnerability in Wireshark Wireshark, published on 29 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service

Weakness: CWE-125, CWE-122

Which versions are affected by CVE-2026-96423?

It affects 1 product.

Products include Wireshark Wireshark.

How do I fix CVE-2026-96423?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-96423 being exploited?

There is no known exploitation of CVE-2026-96423 in the wild and no public exploit code.

All Wireshark Wireshark vulnerabilities

Sources

Also known as AZL-105003, DEBIAN-CVE-2026-96423, GHSA-969r-pwxc-fjq2, MINI-p8xc-c3x3-frwp, UBUNTU-CVE-2026-96423.

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