CVE-2026-72722
Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Medium4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.44% · top 61% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.3.
Weakness
Affected products
References (9)
- https://github.com/discourse/discourse/security/advisories/GHSA-4fx9-5m29-83p4 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/discourse/discourse/pull/42091 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42092 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42093 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/pull/42094 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/45abd925e46e8be40d2d047bced26628f26e4e31 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/7d7ce546ac86e24a6512b321ace69fc52fe37bf4 (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/836a251d54a1004fb1c463a7d299b933b176191f (opens in a new tab)x_refsource_MISC
- https://github.com/discourse/discourse/commit/e54ba27eacee0f14f315e510e287e7ac2e4bdb1a (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-72722)Record last updated .