CVE-2026-31931 Suricata tls: null dereference in tls.alpn rule keyword

High 7.5 Published Updated

A null pointer dereference in Suricata's tls.alpn rule keyword allows attackers to crash the service, requiring specific rule configuration.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-31931?

CVE-2026-31931 is a high-severity vulnerability in Oisf Suricata, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Suricata is a network IDS, IPS and NSM engine. From version 8.0.0 to before version 8.0.4, use of the "tls.alpn" rule keyword can cause Suricata to crash with a NULL dereference. This issue has been patched in version 8.0.4.

Weakness: CWE-476

Which versions are affected by CVE-2026-31931?

It affects 1 product.

Products include Oisf Suricata.

How do I fix CVE-2026-31931?

Upgrade to a fixed version.

Is CVE-2026-31931 being exploited?

There is no known exploitation of CVE-2026-31931 in the wild and no public exploit code.

All Oisf Suricata vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-31931, GHSA-gr22-4784-xvw3, UBUNTU-CVE-2026-31931.

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