What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-09-28
• Weakness: CWE-407

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 products

• OISF suricata: 8.0.5

References

• https://github.com/OISF/suricata/commit/15bf91c5ccbbbf640cd042e1c96974b262549385
• https://github.com/OISF/suricata/commit/82c41905589305e8389ceb793907ccb74798aee5
• https://github.com/OISF/suricata/releases/tag/suricata-8.0.6
• https://github.com/OISF/suricata/security/advisories/GHSA-w394-3g33-3jg9
• https://redmine.openinfosecfoundation.org/issues/8592

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