{"id":"CVE-2022-39955","url":"https://www.cyber-defence.io/tools/cve/CVE-2022-39955","generatedAt":"2026-10-27T20:54:22.525Z","title":"The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes.","description":"The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes. A vulnerable back-end can potentially be exploited by declaring multiple Content-Type \"charset\" names and therefore bypassing the configurable CRS Content-Type header \"charset\" allow list. An encoded payload can bypass CRS detection this way and may then be decoded by the backend. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.","published":"2022-09-20T07:15:12.000Z","lastModified":"2026-06-17T04:58:35.000Z","status":"Modified","sourceIdentifier":"vulnerability@ncsc.ch","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-863"],"affected":["owasp/owasp modsecurity core rule set","fedoraproject/fedora","debian/debian linux"],"epss":{"score":0.01421,"percentile":0.72652,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/","tags":["Patch","Vendor Advisory"],"source":"vulnerability@ncsc.ch"},{"url":"https://lists.debian.org/debian-lts-announce/2023/01/msg00033.html","tags":["Mailing List","Third Party Advisory"],"source":"vulnerability@ncsc.ch"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HL2L2GF7GOCWPMJZDUE5OXDSXHGG3XUJ/","source":"vulnerability@ncsc.ch"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PD56EAYNGB6E6QQH62LAYCONOP6OH5DZ/","source":"vulnerability@ncsc.ch"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPQ6CCMX3MU4A7MTCGQJA7VMJW3IQDXV/","source":"vulnerability@ncsc.ch"},{"url":"https://security.gentoo.org/glsa/202305-25","source":"vulnerability@ncsc.ch"},{"url":"https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2023/01/msg00033.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/08/msg00004.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HL2L2GF7GOCWPMJZDUE5OXDSXHGG3XUJ/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PD56EAYNGB6E6QQH62LAYCONOP6OH5DZ/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPQ6CCMX3MU4A7MTCGQJA7VMJW3IQDXV/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202305-25","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2022-39955","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}