WS-2026-0085
Published:September 30, 2026
Updated:October 01, 2026
libmodsecurity (ModSecurity v3) 3.0.5 through 3.0.16 accepts the RFC 2231 filename* multipart parameter but exposes only the plain filename to MULTIPART_FILENAME/FILES rules, so filename="safe.jpg"; filename*=UTF-8''shell.php passes filename rules while RFC-compliant backends store shell.php. Fixed in 3.0.17. ModSecurity v2 rejects filename* as an invalid Content-Disposition and is not affected.
Affected Packages
https://github.com/owasp-modsecurity/ModSecurity.git (GITHUB):
Affected version(s) >=v3.0.5 <v3.0.17Fix Suggestion:
Update to version v3.0.17Related Resources (2)
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Contact UsCVSS v4
Base Score:
9.2
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE