Suricata app-layer: passed flows can retain transactions, causing resource exhaustion
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-401.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA suricata (OISF) Fixed in 8.0.6
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63446
References
Patch 3
More OISF Suricata vulnerabilities
- TI-2026-33506 ikev2: unbounded client transform storage can lead to resource exhaustion CVSS 3.1HIGH 7.5
- TI-2026-33484 Suricata lua/tls: null dereference in TlsGetCertInfo CVSS 3.1HIGH 7.5
- TI-2024-31811 Suricata ja4: invalid alpn leads to panic CVSS 3.1HIGH 7.5
- TI-2020-13673 Directory Traversal vulnerability found in Pfsense v.2.1.3 and Pfsense Suricata v.1.4.6… CVSS 3.1HIGH 7.5
- TI-2023-17928 In Suricata before 6.0.13, an adversary who controls an external source of Lua rules may… CVSS 3.1CRITICAL 9.8
- TI-2026-63304 Use after free in OISF Suricata CVSS 3.1CRITICAL 9.4
Sources
- CVE-2026-63446 · CVE Program
- CVE-2026-63446 · NVD
- FIRST EPSS
- CVE-2026-63446 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences