Vulnerability in Discourse
CVE-2025-24808
Discourse is an open-source discussion platform. Prior to versions `3.3.4` on the `stable` branch and `3.4.0.beta5` on the `beta` branch, someone who is about to reach the limit of users in a group DM may send requests to add new users in parallel. The requests might all go through ignoring the limit due to a race condition. The patch in versions `3.3.4` and `3.4.0.beta5` uses the `lock` step in service to wrap part of the `add_users_to_channel` service inside a distributed lock/mutex in order to avoid the race condition.
Vulnerability class: Race Condition
EPSS: 0.002 (9.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
Affected products
- Discourse — versions >= 3.4.0.beta1, < 3.4.0.beta5, 3.4.0, < 3.3.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-24808?
- CVE-2025-24808 is a medium-severity vulnerability in Discourse, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.3/10. Published 2025-03-26.
- How severe is CVE-2025-24808?
- Medium severity. CVSS v3 base score is 4.3 out of 10.