{"id":"CVE-2026-52747","title":"ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx","summary":"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-…","severity":"high","cvss":8.6,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","cwe":["CWE-180"],"published":"2026-07-10","updated":"2026-07-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-52747","references":[{"url":"https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7","label":"security-advisories@github.com"},{"url":"https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16","label":"security-advisories@github.com"},{"url":"https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00476,"epssPercentile":0.38415,"ingestedAt":"2026-07-11T22:16:00.520Z","slug":"CVE-2026-52747","body":"## Overview\n\nModSecurity 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":47,"depthScoreParts":{"impact":47.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}