Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/discourse/discourse/commit/1276d7032af8803956c74ae87ccfd97693
- https://github.com/discourse/discourse/commit/45ab6d54076de9ca4965888974d4416d5b
- https://github.com/discourse/discourse/commit/49efe1d7f098f2ce7301908815a211cc92
- https://github.com/discourse/discourse/commit/dc54846f0754799591717b6018343e4952
- 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/security/advisories/GHSA-8g98-fvfc-9w48
FAQ
What is CVE-2026-72724?
CVE-2026-72724 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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 ...
How severe is CVE-2026-72724?
CVE-2026-72724 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-72724?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.