Suricata ftp: crafted FTP traffic can cause quadratic CPU consumption
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-407.
Summary
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.5 until 8.0.6, the FTP parser in src/app-layer-ftp.c can continue allocating transactions after app-layer.protocols.ftp.max-tx is reached while processing one large chunk of FTP command data. The oversized transaction list is repeatedly processed with quadratic complexity after the too_many_transactions event, allowing crafted FTP traffic to degrade packet processing, reduce monitoring visibility, or cause denial of service. 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-2026-63447
- 2026-10-28 EPSS moved to the 50th–90th percentile
References
Patch 2
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-2026-63447 · CVE Program
- CVE-2026-63447 · NVD
- FIRST EPSS
- CVE-2026-63447 · 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