What’s Vulnerable › Vulnerabilities

CVE-2026-63446: Suricata app-layer: passed flows can retain transactions, causing resource exhaustion

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-09-28
• Weakness: CWE-401

Description

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Affected products

• OISF suricata: from 8.0.0 before 8.0.6 — fixed in 8.0.6

How to fix

Upgrade to a fixed version: OISF suricata 8.0.6. Check the vendor advisory for mitigations.

References

• https://github.com/OISF/suricata/commit/006e21c1ccc38c1c815e7945d54b4638cc5f0de8
• https://github.com/OISF/suricata/commit/60a83c62a1dfdfb589b2bad27fb7fc339fc964b7
• https://github.com/OISF/suricata/pull/15726
• https://github.com/OISF/suricata/releases/tag/suricata-8.0.6
• https://github.com/OISF/suricata/security/advisories/GHSA-gjwr-75gq-877m
• https://redmine.openinfosecfoundation.org/issues/8628

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