| Name | CVE-2026-52747 |
| Description | ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 3.0.16, the multipart/form-data request body parser in libmodsecurity silently removes embedded line breaks from non-file form-field values before exporting them to ARGS and ARGS_POST because src/request_body_processor/multipart.cc overwrites reserved bytes in m_reserve instead of appending the current buffer. This creates a parser differential between ModSecurity and backend applications that preserve line breaks in form fields, allowing rules that inspect ARGS or ARGS_POST to miss payloads whose dangerous syntax depends on a line break. This issue is fixed in version 3.0.16. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1141961 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| modsecurity (PTS) | bullseye | 3.0.4-2 | vulnerable |
| bookworm | 3.0.9-1+deb12u2 | vulnerable |
| trixie | 3.0.14-1+deb13u1 | vulnerable |
| forky, sid | 3.0.16-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| modsecurity | source | (unstable) | 3.0.16-1 | | | 1141961 |
Notes
[trixie] - modsecurity <no-dsa> (Minor issue; will be fixed via point release)
[bookworm] - modsecurity <postponed> (Minor issue; multipart parser differential, WAF-rule bypass only)
[bullseye] - modsecurity <postponed> (Minor issue; multipart parser differential, WAF-rule bypass only)
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88
Fixed by: https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7 (v3.0.16)