CVE-2026-52747
Publication date 13 July 2026
Last updated 13 July 2026
Ubuntu priority
Cvss 3 Severity Score
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| modsecurity | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
8.6 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-52747
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88
- https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16