{"id":"CVE-2026-91134","revision":null,"records":[{"revision":"a971efd041464128b0f1b1455a4fd5d5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-91134","aliases":[],"title":"Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist","description":"Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowed_iframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form differently from the stored iframe src, allowing the browser to interpret an attacker-controlled host while the allowlist check accepted the encoded URL as an allowed prefix. An authenticated user with posting privileges could persist the iframe in a post and cause attacker-controlled cross-origin content to be rendered. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.","state":0,"publishedAt":"2026-09-24T16:51:34.057+00:00","modifiedAt":"2026-09-29T02:56:30.376+00:00","affected":[{"ecosystem":"Vendor product","name":"discourse","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"discourse\",\n                    \"product\": \"discourse\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2026.8.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2026.7.0-latest, < 2026.7.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2026.6.0-latest, < 2026.6.3\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2026.1.0-latest, < 2026.1.8\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","score":5.4,"severity":"MEDIUM"}],"references":["https://github.com/discourse/discourse/security/advisories/GHSA-54vw-chv3-wjpv","https://github.com/discourse/discourse/pull/42882","https://github.com/discourse/discourse/commit/0a8015e6c7a5079981843721494d30c9a91f5415","https://github.com/discourse/discourse/commit/1304b0c04f87534053b0d574ae5a9b9ba13dd590","https://github.com/discourse/discourse/commit/bac7dd1201911851462483271b4567246fa1309d","https://github.com/discourse/discourse/commit/fed3a58c48412ce7207b72a4629ddbc44482cd64"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-91134","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-91134","identifiers":["CVE-2026-91134"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-12T07:54:58.2349119+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-12T07:54:58.2349119+00:00","lastSuccessAt":"2026-11-12T07:54:58.4848198+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.4848225+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-64752486c567b55b31fb0d7225f5222bcd0019564ac0ac5f0649e242c7b19299-1225a640a70b576ed1a85d2671a302d70a8e18168f570c1f4912faf8f66b1119","complete":true,"records":424623,"lastAttemptAt":"2026-11-12T07:53:22.876714+00:00","lastSuccessAt":"2026-11-12T07:53:22.8444514+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:53:22.876714+00:00","snapshotPublishedAt":"2026-11-12T07:24:53+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-570328139368428ca550af1570d01579","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T07:55:38.9446123+00:00","lastSuccessAt":"2026-11-12T06:55:06.923+00:00","error":null,"lastVerifiedAt":"2026-11-12T06:55:06.923+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-12T07:54:58.2349119+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-12T07:54:58.2349119+00:00","lastSuccessAt":"2026-11-12T07:54:58.4862124+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.4862143+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-8017f5c1a44c430b920cd4f30d507e78","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T07:55:38.3687422+00:00","lastSuccessAt":"2026-11-12T07:55:38.365+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:55:38.365+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-12T07:54:58.021445+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.021445+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-12T07:53:23.1198989+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:53:23.1198989+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-baa8362b4daf9e5f39d5563775a55935e7b442c0735d33274a921579ce4a0d66","complete":true,"records":3093,"lastAttemptAt":"2026-11-12T07:54:58.1995224+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.1995224+00:00","snapshotPublishedAt":"2026-11-11T12:47:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-3c15e3b4b3da393566ac7be69c095bef52c252ec437d24c4c6ea68ed9e4af0f5","complete":true,"records":231700,"lastAttemptAt":"2026-11-12T07:54:57.8931777+00:00","lastSuccessAt":"2026-11-12T07:54:56.4668314+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:57.8931777+00:00","snapshotPublishedAt":"2026-11-12T07:33:19+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}