CVE-2026-63447: oisf suricata Inefficient Algorithmic Complexity

Vulnerability summary

CVE-2026-63447 is a high (CVSS 7.5) Inefficient Algorithmic Complexity vulnerability in oisf suricata. EPSS estimates a 0.63% chance of exploitation in the next 30 days, higher than 49.4% of scored vulnerabilities.

Timeline

1. 18-09-2026
   PublishedVulnerability first disclosed.
2. 21-09-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-407Inefficient Algorithmic ComplexityAn algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.