CVE-2026-21865
Last modified
CVE-2026-21865 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, moderators can convert some personal messages to public topics when they shouldn't have access. EPSS estimates a 0.22% chance of exploitation in the next 30 days.
Description
Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, moderators can convert some personal messages to public topics when they shouldn't have access. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, site admin can temporarily revoke the moderation role from untrusted moderators or remove the moderator group from the "personal message enabled groups" site setting until the Discourse instance has been upgraded to a version that has been patched.
Metrics
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse | < 3.5.4 |
| Discourse | Discourse | >= 2025.11.0, < 2025.11.2 |
| Discourse | Discourse | 2025.12.0 |
| Discourse | Discourse | 2026.1.0 |
References
- https://github.com/discourse/discourse/security/advisories/GHSA-4777-wrv5-3g39Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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