High severity · published Sep 18, 2026
CVE-2026-63447
Suricata ftp: crafted FTP traffic can cause quadratic CPU consumption
7.5
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SU
suricata · OISF
>= 8.0.5, < 8.0.6 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63447
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63447
Patch
https://github.com/OISF/suricata/commit/15bf91c5ccbbbf640cd042e1c96974b262549385
Patch
https://github.com/OISF/suricata/commit/82c41905589305e8389ceb793907ccb74798aee5
Release Notes
https://github.com/OISF/suricata/releases/tag/suricata-8.0.6
Mitigation
https://github.com/OISF/suricata/security/advisories/GHSA-w394-3g33-3jg9
Permissions Required
https://redmine.openinfosecfoundation.org/issues/8592
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