CVE-2026-6533 Improperly Controlled Sequential Memory Allocation in Wireshark
A crash in the LZ77 decompression engine 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-2026-6533?
CVE-2026-6533 is a medium-severity denial of service vulnerability in Wireshark Wireshark, published on 30 Apr 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
Dissection engine LZ77 decompression crash in Wireshark 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14 allows denial of service
Weakness: CWE-1325
Which versions are affected by CVE-2026-6533?
It affects 1 product.
Products include Wireshark Wireshark.
How do I fix CVE-2026-6533?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-6533 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-6533 exists.
Other vulnerabilities in Wireshark Wireshark
Sources
Also known as AZL-85455, DEBIAN-CVE-2026-6533, GHSA-q3p3-3qhr-3586, UBUNTU-CVE-2026-6533.