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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-02 · updated 2026-10-26
Weakness: CWE-476

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.

Affected products

OISF suricata: from 8.0.0 before 8.0.4 — fixed in 8.0.4

How to fix

Upgrade to a fixed version: OISF suricata 8.0.4. Check the vendor advisory for mitigations.

References

https://github.com/OISF/suricata/security/advisories/GHSA-gr22-4784-xvw3
https://redmine.openinfosecfoundation.org/issues/8294

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