CVE-2026-104269
Description
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.
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| owasp-modsecurity ModSecurity | >= 3.0.0, < 3.0.17 | — |
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