{"id":"CVE-2026-72724","title":"Discourse is an open-source discussion platform","summary":"Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking …","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-639"],"published":"2026-08-10","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:54:37.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72724","references":[{"url":"https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/pull/42091","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/pull/42092","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/pull/42093","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/pull/42094","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00458,"epssPercentile":0.39063,"ingestedAt":"2026-09-08T21:11:12.273Z","slug":"CVE-2026-72724","body":"## Overview\n\nDiscourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking whether the user can preview the selected chat channel. An authenticated user can pair a public channel ID with a private thread ID in a /onebox.json request and obtain private thread message content. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}