{"id":"CVE-2026-72724","summary":"Discourse: Private Chat Threat Message Disclosure via Chat Onebox Channel/Threat ID Mismatch","details":"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.","aliases":["BIT-discourse-2026-72724","GHSA-8g98-fvfc-9w48"],"modified":"2026-09-10T03:30:44.075083120Z","published":"2026-08-10T15:59:53.965Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-639"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72724.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72724.json"},{"type":"ADVISORY","url":"https://github.com/discourse/discourse/security/advisories/GHSA-8g98-fvfc-9w48"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72724"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd976938dcd75"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b48e83c"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc9248270f"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e49524e41ce"},{"type":"FIX","url":"https://github.com/discourse/discourse/pull/42091"},{"type":"FIX","url":"https://github.com/discourse/discourse/pull/42092"},{"type":"FIX","url":"https://github.com/discourse/discourse/pull/42093"},{"type":"FIX","url":"https://github.com/discourse/discourse/pull/42094"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/discourse/discourse","events":[{"introduced":"0"},{"introduced":"640840d818f4ee9375829ece0ef452923bb0c012"},{"introduced":"06d03da34c4ed09ea59f917f045ba250d2b6320d"},{"introduced":"ded677e00beb0e9bae6e70b69582aecfb72b5477"},{"fixed":"94190ccb5176eb4ab1f2b509fcecc3fc682dadae"},{"fixed":"3a87be49d621faddf5cea3f6a090adc9b7cbb7e8"},{"fixed":"b6419ddb26f109092cdc5fdc4b2624fe95a5e8d4"},{"fixed":"ded677e00beb0e9bae6e70b69582aecfb72b5477"},{"fixed":"1276d7032af8803956c74ae87ccfd976938dcd75"},{"fixed":"45ab6d54076de9ca4965888974d4416d5b48e83c"},{"fixed":"49efe1d7f098f2ce7301908815a211cc9248270f"},{"fixed":"dc54846f0754799591717b6018343e49524e41ce"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"2026.1.6"},{"introduced":"2026.5.0-latest"},{"fixed":"2026.5.2"},{"introduced":"2026.6.0-latest"},{"fixed":"2026.6.1"},{"introduced":"2026.7.0-latest"},{"fixed":"2026.7.0"}]}}],"versions":["_gh-attach-assets","v2026.1.5","v2026.5.1","v2026.6.0","v2026.7.0-latest","v2026.5.0","v2026.6.0-latest","v2026.1.4","v2026.5.0-latest.1","v2026.5.0-latest","v2026.1.3","v2026.1.2","v2026.1.1","v2026.1.0","stable","esr","v2026.1.0-latest","v2025.12.0-latest","v3.6.0.beta2","v3.6.0.beta1","v3.5.0.beta9","v3.5.0.beta8","v3.5.0.beta7","v3.5.0.beta6","v3.5.0.beta5","v3.5.0.beta4","v3.5.0.beta3","v3.5.0.beta2","v3.5.0.beta1","v3.4.0.beta4","v3.4.0.beta3","v3.4.0.beta2","v3.4.0.beta1","v3.3.0.beta5","v3.3.0.beta6","v3.3.0.beta4","v3.3.0.beta3","v3.3.0.beta2","v3.3.0.beta1","v3.2.0.beta5","v3.2.0.beta4","v3.2.0.beta3","v3.2.0.beta2","v3.2.0.beta1","v3.1.0.beta8","v3.1.0.beta7","v3.1.0.beta6","v3.1.0.beta5","v3.1.0.beta4","v3.1.0.beta3","v3.1.0.beta2","v3.1.0.beta1","v3.0.0.beta16","v3.0.0.beta15","v2.9.0.beta14","v2.9.0.beta13","v2.9.0.beta12","v2.9.0.beta11","v2.9.0.beta10","v2.9.0.beta9","v2.9.0.beta8","v2.9.0.beta7","v2.9.0.beta6","v2.9.0.beta5","v2.9.0.beta4","v2.9.0.beta3","v2.9.0.beta2","v2.9.0.beta1","v2.8.0.beta11","v2.8.0.beta10","v2.8.0.beta9","v2.8.0.beta8","v2.8.0.beta7","v2.8.0.beta6","v2.8.0.beta5","v2.8.0.beta4","v2.8.0.beta3","v2.8.0.beta2","v2.8.0.beta1","v2.7.0.beta9","v2.7.0.beta8","v2.7.0.beta7","v2.7.0.beta6","v2.7.0.beta5","v2.7.0.beta4","v2.7.0.beta3","v2.7.0.beta2","v2.7.0.beta1","v2.6.0.beta6","v2.6.0.beta5","v2.6.0.beta4","v2.6.0.beta3","v2.6.0.beta2","v2.6.0.beta1","v2.5.0.beta7","v2.5.0.beta6","v2.5.0.beta5","v2.5.0.beta4","v2.5.0.beta3","v2.5.0.beta2","v2.5.0.beta1","v2.4.0.beta11","v2.4.0.beta10","v2.4.0.beta9","v2.4.0.beta8","v2.4.0.beta7","v2.4.0.beta6","v2.4.0.beta5","v2.4.0.beta4","v2.4.0.beta3","v2.4.0.beta2","v2.4.0.beta1","v2.3.0.beta11","v2.3.0.beta10","v2.3.0.beta9","v2.3.0.beta8","v2.3.0.beta7","v2.3.0.beta6","v2.3.0.beta5","v2.3.0.beta4","v2.3.0.beta3","v2.3.0.beta2","v2.3.0.beta1","v2.2.0.beta10","v2.2.0.beta9","v2.2.0.beta8","v2.2.0.beta7","v2.2.0.beta6","v2.2.0.beta5","v2.2.0.beta4","v2.2.0.beta3","v2.2.0.beta2","v2.2.0.beta1","v2.1.0.beta6","v2.1.0.beta5","v2.1.0.beta4","v2.1.0.beta3","v2.1.0.beta2","v2.1.0.beta1","v2.0.0.beta10","v2.0.0.beta9","v2.0.0.beta8","v2.0.0.beta7","v2.0.0.beta6","v2.0.0.beta5","v2.0.0.beta4","v2.0.0.beta3","v2.0.0.beta2","v2.0.0.beta1","v1.9.0.beta17","v1.9.0.beta16","v1.9.0.beta15","v1.9.0.beta14","v1.9.0.beta13","v1.9.0.beta12","v1.9.0.beta11","v1.9.0.beta10","v1.9.0.beta9","v1.9.0.beta8","v1.9.0.beta7","v1.9.0.beta6","v1.9.0.beta5","v1.9.0.beta4","v1.9.0.beta3","v1.9.0.beta2","v1.9.0.beta1","v1.8.0.beta13","v1.8.0.beta12","v1.8.0.beta11","v1.8.0.beta10","v1.8.0.beta9","v1.8.0.beta8","v1.8.0.beta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