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Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M

CVE-2026-63447Suricata ftp: crafted FTP traffic can cause quadratic CPU consumption

High 7.5

In plain English

A high-severity security flaw in suricata from OISF. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 49.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13suricatano fix listedDEBIAN-CVE-2026-63447
Debian:14suricata1:8.0.6-1DEBIAN-CVE-2026-63447
Ubuntu:22.04:LTSsuricatano fix listedUBUNTU-CVE-2026-63447
Ubuntu:24.04:LTSsuricatano fix listedUBUNTU-CVE-2026-63447
Ubuntu:26.04:LTSsuricatano fix listedUBUNTU-CVE-2026-63447

Affected products (as reported)

VendorProductVersions
OISF suricata >= 8.0.5, < 8.0.6

Weakness: CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References