{"id":"BIT-modsecurity-2026-52747","summary":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","details":"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.","aliases":["CVE-2026-52747","GHSA-rcw9-2f5r-7p88"],"modified":"2026-09-08T08:48:14.033641229Z","published":"2026-07-15T08:51:29.972Z","database_specific":{"cpes":["cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:*"],"severity":"High"},"references":[{"type":"FIX","url":"https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7"},{"type":"ARTICLE","url":"https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16"},{"type":"ADVISORY","url":"https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52747"}],"affected":[{"package":{"name":"modsecurity","ecosystem":"Bitnami","purl":"pkg:bitnami/modsecurity"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.16"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/modsecurity/BIT-modsecurity-2026-52747.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N"}]}],"schema_version":"1.9.0"}