CVE-2026-27021 Discourse: Poll voters endpoint lacked post visibility checks
Attackers can view voter details for polls in any post, including private ones, due to missing visibility checks in the Discourse poll plugin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-27021?
CVE-2026-27021 is a medium-severity missing authorization vulnerability in Discourse Discourse, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, 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, the voters endpoint in the poll plugin lacked post visibility checks which allowed unauthorized access to voters details of polls in any post. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
Weakness: CWE-862
Which versions are affected by CVE-2026-27021?
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-2026-27021?
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-2026-27021 being exploited?
There is no known exploitation of CVE-2026-27021 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-2026-27021, GHSA-f5m5-9hpw-7c2g.