{"id":"CVE-2026-72722","aliases":["BIT-discourse-2026-72722","EUVD-2026-55659","GHSA-4fx9-5m29-83p4"],"status":"published","title":"Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00442,"percentile":0.38715,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-862"],"published":"2026-08-10T15:54:35Z","modified":"2026-10-28T02:30:51Z","fixes":[{"ecosystem":"Bitnami","package":"discourse","fixed_in":["2026.1.6","2026.5.2","2026.6.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"discourse","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.1.6"},{"introduced":"2026.5.0"},{"fixed":"2026.5.2"},{"introduced":"2026.6.0"},{"fixed":"2026.6.1"}]}]}],"products":[{"vendor":"discourse","product":"discourse"}],"references":[{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-4fx9-5m29-83p4","tags":["x_refsource_CONFIRM","web","advisory"]},{"url":"https://github.com/discourse/discourse/pull/42091","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/pull/42092","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/pull/42093","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/pull/42094","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/commit/45abd925e46e8be40d2d047bced26628f26e4e31","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/commit/7d7ce546ac86e24a6512b321ace69fc52fe37bf4","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/commit/836a251d54a1004fb1c463a7d299b933b176191f","tags":["x_refsource_MISC","web","fix"]},{"url":"https://github.com/discourse/discourse/commit/e54ba27eacee0f14f315e510e287e7ac2e4bdb1a","tags":["x_refsource_MISC","web","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72722","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72722.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-72722","title":"Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","status":"published","published":"2026-08-10T15:54:35.907Z","modified":"2026-08-13T17:46:27.779Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:19:52.016971Z"}],"euvd":[{"id":"EUVD-2026-55659","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","status":"published","published":"2026-08-10T15:54:35Z","modified":"2026-08-13T17:46:27Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:01:55.61982Z"}],"nvd":[{"id":"CVE-2026-72722","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","status":"published","published":"2026-08-10T16:19:49.52Z","modified":"2026-09-08T20:54:37.79Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:12:36.102748Z"}],"osv":[{"id":"CVE-2026-72722","title":"Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","status":"published","published":"2026-08-10T15:54:35.907Z","modified":"2026-10-28T02:30:51.118141822Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T15:45:15.88521Z"},{"id":"BIT-discourse-2026-72722","title":"Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs","description":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.","status":"published","published":"2026-08-17T05:44:22.723Z","modified":"2026-08-17T08:10:41.155430795Z","updated_at":"2026-11-02T15:28:29.152062Z"}]}}