CVE-2025-24808: discourse — Fix

Description

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.

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CVSS v3.1 Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Weakness Type (CWE)

CWE-362 CWE-362

Affected Products

Vendor	Product	Versions
discourse	discourse	< 3.3.3
discourse	discourse	< 3.4.0
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All

References

Advisories & Patches

https://github.com/discourse/discourse/commit/a16b2f224860f6678f89f5ffa012f0ede17e4095 https://github.com/discourse/discourse/security/advisories/GHSA-hfcx-qjw6-573r

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2025-24808? +

CVE-2025-24808 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-24808? +

CVE-2025-24808 affects products from discourse, specifically: discourse. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-24808? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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