{"id":"CVE-2026-63670","state":"PUBLISHED","title":"ApostropheCMS: Mutation-XSS / allowedTags bypass via literal `</textarea/>` solidus close","description":"ApostropheCMS is an open-source Node.js content management system. Prior to 2.17.6, sanitizeHtml() can pass disallowed executable markup through packages/sanitize-html/index.js when textarea or xmp is included in allowedTags because a literal solidus after the raw-text end-tag name is treated as text by htmlparser2 and the ontext handler emits that content without escaping, while a browser parses the following img onerror markup as active HTML. This issue is fixed in version 2.17.6.","publishedAt":"2026-08-17T19:49:51.903Z","updatedAt":"2026-08-18T18:08:30.331Z","severity":{"score":6.1,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["apostrophecms apostrophe"],"affected":[{"vendor":"apostrophecms","product":"apostrophe","versions":[{"version":"< 2.17.6","status":"affected"}]}],"references":["https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-jxwj-j7wr-gfrw","https://github.com/apostrophecms/apostrophe/pull/5501","https://github.com/apostrophecms/apostrophe/commit/eae1fb2b72ec5d1c27d0977509c6482a0408f725"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63670.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63670","state":"PUBLISHED","datePublished":"2026-08-17T19:49:51.903Z","dateUpdated":"2026-08-18T18:08:30.331Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-17T14:47:08.032Z"},"containers":{"cna":{"title":"ApostropheCMS: Mutation-XSS / allowedTags bypass via literal `</textarea/>` solidus close","descriptions":[{"lang":"en","value":"ApostropheCMS is an open-source Node.js content management system. Prior to 2.17.6, sanitizeHtml() can pass disallowed executable markup through packages/sanitize-html/index.js when textarea or xmp is included in allowedTags because a literal solidus after the raw-text end-tag name is treated as text by htmlparser2 and the ontext handler emits that content without escaping, while a browser parses the following img onerror markup as active HTML. This issue is fixed in version 2.17.6."}],"affected":[{"vendor":"apostrophecms","product":"apostrophe","versions":[{"version":"< 2.17.6","status":"affected"}]}],"references":[{"url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-jxwj-j7wr-gfrw","name":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-jxwj-j7wr-gfrw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/apostrophecms/apostrophe/pull/5501","name":"https://github.com/apostrophecms/apostrophe/pull/5501","tags":["x_refsource_MISC"]},{"url":"https://github.com/apostrophecms/apostrophe/commit/eae1fb2b72ec5d1c27d0977509c6482a0408f725","name":"https://github.com/apostrophecms/apostrophe/commit/eae1fb2b72ec5d1c27d0977509c6482a0408f725","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.1,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"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":"2026-08-17T19:49:51.903Z"},"source":{"advisory":"GHSA-jxwj-j7wr-gfrw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-jxwj-j7wr-gfrw","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T18:07:52.564054Z","id":"CVE-2026-63670","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":"2026-08-18T18:08:30.331Z"}}]}}}