{"id":"CVE-2026-41240","state":"PUBLISHED","title":"DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)","description":"DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.","publishedAt":"2026-04-23T14:54:32.426Z","updatedAt":"2026-04-23T17:21:30.547Z","severity":{"score":6,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["cure53 DOMPurify"],"affected":[{"vendor":"cure53","product":"DOMPurify","versions":[{"version":"< 3.4.0","status":"affected"}]}],"references":["https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m","https://github.com/cure53/DOMPurify/commit/c361baa18dbdcb3344a41110f4c48ad85bf48f80","https://github.com/cure53/DOMPurify/releases/tag/3.4.0"],"weaknesses":["CWE-183","CWE-79"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/41xxx/CVE-2026-41240.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-41240","state":"PUBLISHED","datePublished":"2026-04-23T14:54:32.426Z","dateUpdated":"2026-04-23T17:21:30.547Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-18T03:47:03.135Z"},"containers":{"cna":{"title":"DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)","descriptions":[{"lang":"en","value":"DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue."}],"affected":[{"vendor":"cure53","product":"DOMPurify","versions":[{"version":"< 3.4.0","status":"affected"}]}],"references":[{"url":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m","name":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/cure53/DOMPurify/commit/c361baa18dbdcb3344a41110f4c48ad85bf48f80","name":"https://github.com/cure53/DOMPurify/commit/c361baa18dbdcb3344a41110f4c48ad85bf48f80","tags":["x_refsource_MISC"]},{"url":"https://github.com/cure53/DOMPurify/releases/tag/3.4.0","name":"https://github.com/cure53/DOMPurify/releases/tag/3.4.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-183","lang":"en","description":"CWE-183: Permissive List of Allowed Inputs","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-23T14:54:32.426Z"},"source":{"advisory":"GHSA-h7mw-gpvr-xq4m","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-23T17:21:26.630611Z","id":"CVE-2026-41240","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-23T17:21:30.547Z"}}]}}}