{"id":"CVE-2026-91132","state":"PUBLISHED","title":"Discourse: Wildcard iframe origin allowlist bypass via authority separators","description":"Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched the allowed domain text, while browser URL parsing selected a different attacker-controlled origin. A user with posting privileges could exploit the flaw through a post or a Onebox oEmbed response and cause an attacker-controlled iframe to be rendered independently of the allowlisted domain. Successful exploitation requires a site-configured wildcard iframe pattern and the ability to create a post or trigger an oEmbed request for an attacker-controlled URL. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.","publishedAt":"2026-09-24T16:57:43.082Z","updatedAt":"2026-09-29T02:57:34.925Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["discourse discourse"],"affected":[{"vendor":"discourse","product":"discourse","versions":[{"version":"< 2026.8.0","status":"affected"},{"version":">= 2026.7.0-latest, < 2026.7.2","status":"affected"},{"version":">= 2026.6.0-latest, < 2026.6.3","status":"affected"},{"version":">= 2026.1.0-latest, < 2026.1.8","status":"affected"}]}],"references":["https://github.com/discourse/discourse/security/advisories/GHSA-4q3q-hph3-3rvp","https://github.com/discourse/discourse/pull/42882","https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5","https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a","https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9","https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56"],"weaknesses":["CWE-346"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/91xxx/CVE-2026-91132.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-91132","state":"PUBLISHED","datePublished":"2026-09-24T16:57:43.082Z","dateUpdated":"2026-09-29T02:57:34.925Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-14T19:36:48.844Z"},"containers":{"cna":{"title":"Discourse: Wildcard iframe origin allowlist bypass via authority separators","descriptions":[{"lang":"en","value":"Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched the allowed domain text, while browser URL parsing selected a different attacker-controlled origin. A user with posting privileges could exploit the flaw through a post or a Onebox oEmbed response and cause an attacker-controlled iframe to be rendered independently of the allowlisted domain. Successful exploitation requires a site-configured wildcard iframe pattern and the ability to create a post or trigger an oEmbed request for an attacker-controlled URL. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0."}],"affected":[{"vendor":"discourse","product":"discourse","versions":[{"version":"< 2026.8.0","status":"affected"},{"version":">= 2026.7.0-latest, < 2026.7.2","status":"affected"},{"version":">= 2026.6.0-latest, < 2026.6.3","status":"affected"},{"version":">= 2026.1.0-latest, < 2026.1.8","status":"affected"}]}],"references":[{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-4q3q-hph3-3rvp","name":"https://github.com/discourse/discourse/security/advisories/GHSA-4q3q-hph3-3rvp","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/discourse/discourse/pull/42882","name":"https://github.com/discourse/discourse/pull/42882","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5","name":"https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a","name":"https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9","name":"https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56","name":"https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-346","lang":"en","description":"CWE-346: Origin Validation Error","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-24T16:57:43.082Z"},"source":{"advisory":"GHSA-4q3q-hph3-3rvp","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-29T02:57:23.434341Z","id":"CVE-2026-91132","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-29T02:57:34.925Z"}}]}}}