CVE-2026-104269: ModSecurity: RFC 2231 `filename*` Parameter Bypasses Multipart Filename Rules on RFC-Compliant Backends (Go, Python, Node, Java)

1. In CISA KEV: not seen
2. Exploited (reported): not seen
3. Scanning observed: not seen
4. Proof of concept public: not seen
5. Not establishedNothing in the sources we check

DescriptionNVD

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 until 3.0.17, ModSecurity's multipart parser does not apply the RFC 2231 filename parameter precedence used by common Go, Python, Node.js, and Java application parsers. A Content-Disposition header can provide a benign filename parameter for ModSecurity and a different encoded filename value that the backend prefers, causing MULTIPART_FILENAME rules and the application to make security decisions on different names. Applications that use the backend-selected name for storage, extension checks, or content-type inference can therefore receive a filename that bypassed WAF inspection. PHP's native multipart parser is not affected by this discrepancy. This issue is fixed in version 3.0.17.

• Red Hat Enterprise Linux 10Under investigationchecked 9 Nov 05:00 UTC
• Red Hat Enterprise Linux 9Under investigationchecked 9 Nov 05:00 UTC
• Red Hat Enterprise Linux 8Under investigationchecked 9 Nov 05:00 UTC
• Debian 13Affected, no fix releasedchecked 9 Nov 05:00 UTC
• Debian 12Affected, no fix releasedchecked 9 Nov 05:00 UTC

1. 9 Nov
   Debian’s tracker lists Debian 12 as affected, with no fix released Debian
2. 9 Nov
   Debian’s tracker lists Debian 13 as affected, with no fix released Debian
3. 9 Nov
   Red Hat’s tracker lists RHEL 10 as under investigation Red Hat
4. 9 Nov
   Red Hat’s tracker lists RHEL 7 as under investigation Red Hat
5. 9 Nov
   Red Hat’s tracker lists RHEL 8 as under investigation Red Hat
6. 9 Nov
   Red Hat’s tracker lists RHEL 9 as under investigation Red Hat

• NVD entrynvd.nist.gov
• Vendor advisorygithub.com
• CVE recordcve.org