CVE-2026-26207 DIscourse's discourse-policy plugin lacks post access check
Authenticated users can modify policies on hidden posts and enumerate policy attachments due to missing access checks in the Discourse policy plugin.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-26207?
CVE-2026-26207 is a medium-severity missing authorization vulnerability in Discourse Discourse, published on 26 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, `discourse-policy` plugin allows any authenticated user to interact with policies on posts they do not have permission to view. The `PolicyController` loads posts by ID without verifying the current user's access, enabling policy group members to accept/unaccept policies on posts in private categories or PMs they cannot see and any authenticated user to enumerate which post IDs have policies attached via differentiated error responses (information disclosure). The issue is patched in versions 2025.12.2, 2026.1.1, and 2026.2.0 by adding a `guardian.can_see?(@post)` check in the `set_post` before_action, ensuring post visibility is verified before any policy action is processed. As a workaround, disabling the discourse-policy plugin (`policy_enabled = false`) eliminates the vulnerability. There is no other workaround without upgrading.
Weakness: CWE-862
Which versions are affected by CVE-2026-26207?
1 open source package ship an affected version, including discourse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
discourse Bitnami | All versions | 2025.12.2, 2026.1.1 |
Products include Discourse Discourse.
How do I fix CVE-2026-26207?
Upgrade discourse to a fixed version for your release line: 2025.12.2 or 2026.1.1.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-26207 being exploited?
There is no known exploitation of CVE-2026-26207 in the wild and no public exploit code.
Other vulnerabilities in Discourse Discourse
- CVE-2021-41163 RCE via malicious SNS subscription payload
- CVE-2022-36066 Discourse vulnerable to RCE via admins uploading maliciously zipped file
- CVE-2022-39356 Discourse user account takeover via email and invite link
- CVE-2023-22468 Discourse vulnerable to Cross-site Scripting in local oneboxes
- CVE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint
Sources
Also known as BIT-discourse-2026-26207, GHSA-jr4h-w6p5-w55r.