# CVE-2026-63446: Suricata inverted flag logic in transaction cleanup

Source: https://junglewise.ai/threats/cve-2026-63446-suricata-is-a-network-intrusion-detection-system-intrusion  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-63446 · Severity: high · CVSS 7.5 · Published 2026-09-18

Suricata is a network security monitoring engine used to detect and prevent intrusions. An inverted logic bug in its transaction handling causes completed connections on pass-rule flows to never be marked as inspected, leading to memory leaks and CPU exhaustion as transaction lists grow without bound and are repeatedly rescanned. This can degrade or disable intrusion detection and prevention on networks handling significant traffic.

Technologies: [OISF Suricata](https://junglewise.ai/threats/technologies/suricata). Vendors: [OISF](https://junglewise.ai/threats/vendors/oisf).

## Quick answers

**Is CVE-2026-63446 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-63446 being exploited in the wild.

**How severe is CVE-2026-63446?** High severity, with a CVSS score of 7.5, published 18 September 2026.

**Which products and versions are affected?** OISF Suricata 8.0.0 to 8.0.5.

**Is there a fix for CVE-2026-63446?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-63446 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-63446?** Check whether you run OISF Suricata at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard condition (checking for presence of a flag instead of absence), marking only already-inspected transactions as inspected rather than newly-completed ones. On pass-rule flows, detection is skipped so the flag is never set by DetectRunTx(), leaving transactions in the per-flow list; this causes quadratic O(n²) cleanup cost as each packet re-scans and rescans the accumulating list. An attacker or legitimate traffic pattern matching pass rules can trigger unbounded transaction accumulation and memory/CPU exhaustion.

## Affected products

- OISF Suricata 8.0.0 to 8.0.5

## Timeline

- 2026-09-18: disclosed

## References

- [https://github.com/OISF/suricata/commit/006e21c1ccc38c1c815e7945d54b4638cc5f0de8](https://github.com/OISF/suricata/commit/006e21c1ccc38c1c815e7945d54b4638cc5f0de8)
- [https://github.com/OISF/suricata/commit/60a83c62a1dfdfb589b2bad27fb7fc339fc964b7](https://github.com/OISF/suricata/commit/60a83c62a1dfdfb589b2bad27fb7fc339fc964b7)

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