{"id":"CVE-2026-91123","published":"2026-09-24T17:17:08.560","lastModified":"2026-09-24T18:19:06.883","description":"Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowed_iframes subpath check while browser URL normalization moved the iframe outside the intended allowed path. The resulting iframe could load content from a location that the administrator did not allow. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.","cvssScore":7.2,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","cwes":["CWE-22"],"vendors":[],"products":[],"references":[{"url":"https://github.com/discourse/discourse/commit/042d7b159beda4f74d23e245e8b2e396d9ff8318","tags":[]},{"url":"https://github.com/discourse/discourse/commit/097ce5600a2d74d9c68e57974597ab2684bd2a24","tags":[]},{"url":"https://github.com/discourse/discourse/commit/0b5a27e689925edce9ba9b14110022435d2b94be","tags":[]},{"url":"https://github.com/discourse/discourse/commit/142f5155ad8e56ddb8012c4e70c69a03dedc0579","tags":[]},{"url":"https://github.com/discourse/discourse/pull/42882","tags":[]},{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-6pwj-wgg8-4rjc","tags":[]}],"exploitRefs":[{"url":"https://github.com/discourse/discourse/commit/042d7b159beda4f74d23e245e8b2e396d9ff8318","tags":[]},{"url":"https://github.com/discourse/discourse/commit/097ce5600a2d74d9c68e57974597ab2684bd2a24","tags":[]},{"url":"https://github.com/discourse/discourse/commit/0b5a27e689925edce9ba9b14110022435d2b94be","tags":[]},{"url":"https://github.com/discourse/discourse/commit/142f5155ad8e56ddb8012c4e70c69a03dedc0579","tags":[]},{"url":"https://github.com/discourse/discourse/pull/42882","tags":[]},{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-6pwj-wgg8-4rjc","tags":[]}],"hasPoc":true,"ai":null}