CVE-2026-31933 Suricata stream: quadratic complexity in stream inspection

High 7.5 Published 2 Apr 2026 Updated 3 Apr 2026

Attackers can cause Suricata to slow down significantly via crafted traffic, impacting IDS performance. Administrators should upgrade to patched versions.

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

What is CVE-2026-31933?

CVE-2026-31933 is a high-severity denial of service 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. Prior to versions 7.0.15 and 8.0.4, specially crafted traffic can cause Suricata to slow down, affecting performance in IDS mode. This issue has been patched in versions 7.0.15 and 8.0.4.

Weakness: CWE-407

Which versions are affected by CVE-2026-31933?

It affects 1 product.

Products include Oisf Suricata.

How do I fix CVE-2026-31933?

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-2026-31933 being exploited?

There is no known exploitation of CVE-2026-31933 in the wild and no public exploit code.

All Oisf Suricata vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-31933, GHSA-hvp5-gpr6-j4gp, UBUNTU-CVE-2026-31933.