{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-21876","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-01-05T17:24:36.927Z","datePublished":"2026-01-08T13:55:37.102Z","dateUpdated":"2026-04-09T15:41:17.073Z"},"containers":{"cna":{"title":"OWASP CRS has multipart bypass using multiple content-type parts","problemTypes":[{"descriptions":[{"cweId":"CWE-794","lang":"en","description":"CWE-794: Incomplete Filtering of Multiple Instances of Special Elements","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/coreruleset/coreruleset/security/advisories/GHSA-36fv-25j3-r2c5","tags":["x_refsource_CONFIRM"],"url":"https://github.com/coreruleset/coreruleset/security/advisories/GHSA-36fv-25j3-r2c5"},{"name":"https://github.com/coreruleset/coreruleset/commit/80d80473abf71bd49bf6d3c1ab221e3c74e4eb83","tags":["x_refsource_MISC"],"url":"https://github.com/coreruleset/coreruleset/commit/80d80473abf71bd49bf6d3c1ab221e3c74e4eb83"},{"name":"https://github.com/coreruleset/coreruleset/commit/9917985de09a6cf38b3261faf9105e909d67a7d6","tags":["x_refsource_MISC"],"url":"https://github.com/coreruleset/coreruleset/commit/9917985de09a6cf38b3261faf9105e909d67a7d6"},{"name":"https://github.com/coreruleset/coreruleset/releases/tag/v3.3.8","tags":["x_refsource_MISC"],"url":"https://github.com/coreruleset/coreruleset/releases/tag/v3.3.8"},{"name":"https://github.com/coreruleset/coreruleset/releases/tag/v4.22.0","tags":["x_refsource_MISC"],"url":"https://github.com/coreruleset/coreruleset/releases/tag/v4.22.0"}],"affected":[{"vendor":"coreruleset","product":"coreruleset","versions":[{"version":"< 4.22.0","status":"affected"},{"version":"< 3.3.8","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-01-08T13:55:37.102Z"},"descriptions":[{"lang":"en","value":"The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 4.22.0 and 3.3.8, the current rule 922110 has a bug when processing multipart requests with multiple parts. When the first rule in a chain iterates over a collection (like `MULTIPART_PART_HEADERS`), the capture variables (`TX:0`, `TX:1`) get overwritten with each iteration. Only the last captured value is available to the chained rule, which means malicious charsets in earlier parts can be missed if a later part has a legitimate charset. Versions 4.22.0 and 3.3.8 patch the issue."}],"source":{"advisory":"GHSA-36fv-25j3-r2c5","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/daytriftnewgen/CVE-2026-21876","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-08T14:52:48.615550Z","id":"CVE-2026-21876","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-09T15:41:17.073Z"}}]}}