{"id":"CVE-2026-52747","aliases":["AZL-92267","BIT-modsecurity-2026-52747","BIT-modsecurity2-2026-52747","DEBIAN-CVE-2026-52747","EUVD-2026-43047","GHSA-rcw9-2f5r-7p88","UBUNTU-CVE-2026-52747"],"status":"published","title":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","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.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00476,"percentile":0.41589,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-180"],"published":"2026-07-10T21:42:11Z","modified":"2026-11-05T05:36:30Z","fixes":[{"ecosystem":"Bitnami","package":"modsecurity","fixed_in":["3.0.16"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"modsecurity","fixed_in":["3.0.16-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Azure Linux:3","package":"mod_security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.9.7-8"}]}]},{"source":"osv","ecosystem":"Bitnami","package":"modsecurity","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.16"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.10-1","3.0.11-1","3.0.12-1","3.0.12-1.1","3.0.12-1.1~exp1","3.0.13-1","3.0.14-1","3.0.15-1","3.0.16-1","3.0.9-1","3.0.9-1+deb12u1","3.0.9-1+deb12u2"]},{"source":"osv","ecosystem":"Debian:13","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.14-1","3.0.14-1+deb13u1","3.0.15-1","3.0.16-1"]},{"source":"osv","ecosystem":"Debian:14","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.16-1"}]}],"versions":["3.0.14-1","3.0.15-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.3-1","3.0.4-1","3.0.4-1build1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.4-2","3.0.6-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.10-1","3.0.11-1","3.0.12-1","3.0.12-1.1build1","3.0.12-1.1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.14-1build2","3.0.15-1","3.0.16-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"modsecurity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.14-1build1","3.0.14-1build2"]}],"products":[{"vendor":"owasp","product":"modsecurity"},{"vendor":"owasp-modsecurity","product":"modsecurity"}],"references":[{"url":"https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88","tags":["x_refsource_CONFIRM","exploit","Exploit","Mitigation","Vendor Advisory","advisory","web","report"]},{"url":"https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7","tags":["x_refsource_MISC","Patch","fix","web","report"]},{"url":"https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16","tags":["x_refsource_MISC","Product","Release Notes","article","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52747","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52747.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-52747","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-52747","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-52747","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-52747","title":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","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":"published","published":"2026-07-10T21:42:11.503Z","modified":"2026-07-13T17:48:27.282Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-180"],"updated_at":"2026-11-02T13:40:57.334596Z"}],"euvd":[{"id":"EUVD-2026-43047","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":"published","published":"2026-07-10T21:42:11Z","modified":"2026-07-13T17:48:27Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:01.134466Z"}],"nvd":[{"id":"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.","status":"published","published":"2026-07-10T22:16:42.697Z","modified":"2026-10-25T15:10:00.147Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-180"],"updated_at":"2026-11-02T14:12:28.771746Z"}],"osv":[{"id":"CVE-2026-52747","title":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","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":"published","published":"2026-07-10T21:42:11.503Z","modified":"2026-11-11T13:04:14.945213878Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-180"],"updated_at":"2026-11-11T03:22:04.464623Z"},{"id":"DEBIAN-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.","status":"published","published":"2026-07-10T22:16:42.697Z","modified":"2026-10-26T11:47:30.52510281Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:56.877408Z"},{"id":"UBUNTU-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.","status":"published","published":"2026-07-10T22:16:00Z","modified":"2026-10-17T12:58:34.215044834Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T16:56:33.391918Z"},{"id":"AZL-92267","title":"CVE-2026-52747 affecting package mod_security 2.9.7-8","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":"published","published":"2026-07-10T22:16:42Z","modified":"2026-11-05T05:36:30Z","updated_at":"2026-11-05T16:41:25.880689Z"},{"id":"BIT-modsecurity-2026-52747","title":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","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":"published","published":"2026-07-15T08:51:29.972Z","modified":"2026-09-08T08:48:14.033641229Z","updated_at":"2026-11-02T15:28:33.072289Z"},{"id":"BIT-modsecurity2-2026-52747","title":"ModSecurity: Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass","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":"withdrawn","published":"2026-07-15T08:51:47.912Z","modified":"2026-07-21T18:15:04.41921487Z","updated_at":"2026-11-02T15:28:33.072289Z"}]}}