{"id":"UBUNTU-CVE-2026-52747","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.","modified":"2026-07-15T19:48:21.334338276Z","published":"2026-07-10T22:16:00Z","upstream":["CVE-2026-52747"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-52747"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-52747"},{"type":"REPORT","url":"https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88"},{"type":"REPORT","url":"https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7"},{"type":"REPORT","url":"https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16"}],"affected":[{"package":{"name":"modsecurity","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/modsecurity?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.3-1","3.0.4-1","3.0.4-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.0.4-1build1","binary_name":"libmodsecurity3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52747.json"}},{"package":{"name":"modsecurity","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/modsecurity?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.4-2","3.0.6-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libmodsecurity3","binary_version":"3.0.6-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52747.json"}},{"package":{"name":"modsecurity","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/modsecurity?arch=source&distro=noble"},"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"],"ecosystem_specific":{"binaries":[{"binary_name":"libmodsecurity3t64","binary_version":"3.0.12-1.1build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52747.json"}},{"package":{"name":"modsecurity","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/modsecurity?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.14-1build1","3.0.14-1build2"],"ecosystem_specific":{"binaries":[{"binary_name":"libmodsecurity3t64","binary_version":"3.0.14-1build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52747.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}