{"id":"CVE-2026-72724","state":"PUBLISHED","title":"Discourse: Private Chat Threat Message Disclosure via Chat Onebox Channel/Threat ID Mismatch","description":"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 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.","publishedAt":"2026-08-10T15:59:53.965Z","updatedAt":"2026-08-11T01:57:42.639Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["discourse discourse"],"affected":[{"vendor":"discourse","product":"discourse","versions":[{"version":"< 2026.1.6","status":"affected"},{"version":">= 2026.5.0-latest, < 2026.5.2","status":"affected"},{"version":">= 2026.6.0-latest, < 2026.6.1","status":"affected"},{"version":">= 2026.7.0-latest, < 2026.7.0","status":"affected"}]}],"references":["https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48","https://github.com/discourse/discourse/pull/42091","https://github.com/discourse/discourse/pull/42092","https://github.com/discourse/discourse/pull/42093","https://github.com/discourse/discourse/pull/42094","https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75","https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c","https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f","https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72724.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72724","state":"PUBLISHED","datePublished":"2026-08-10T15:59:53.965Z","dateUpdated":"2026-08-11T01:57:42.639Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-10T13:48:09.545Z"},"containers":{"cna":{"title":"Discourse: Private Chat Threat Message Disclosure via Chat Onebox Channel/Threat ID Mismatch","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"discourse","product":"discourse","versions":[{"version":"< 2026.1.6","status":"affected"},{"version":">= 2026.5.0-latest, < 2026.5.2","status":"affected"},{"version":">= 2026.6.0-latest, < 2026.6.1","status":"affected"},{"version":">= 2026.7.0-latest, < 2026.7.0","status":"affected"}]}],"references":[{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48","name":"https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/discourse/discourse/pull/42091","name":"https://github.com/discourse/discourse/pull/42091","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/pull/42092","name":"https://github.com/discourse/discourse/pull/42092","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/pull/42093","name":"https://github.com/discourse/discourse/pull/42093","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/pull/42094","name":"https://github.com/discourse/discourse/pull/42094","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75","name":"https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c","name":"https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f","name":"https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f","tags":["x_refsource_MISC"]},{"url":"https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce","name":"https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639: Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-10T15:59:53.965Z"},"source":{"advisory":"GHSA-8g98-fvfc-9w48","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-11T01:57:32.913192Z","id":"CVE-2026-72724","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":"2026-08-11T01:57:42.639Z"}}]}}}