CVE-2022-41921 — Discourse is an open-source discussion platform

Discourse is an open-source discussion platform. Prior to version 2.9.0.beta13, users can post chat messages of an unlimited length, which can cause a denial of service for other users when posting huge amounts of text. Users should upgrade to version 2.9.0.beta13, where a limit

01What is this vulnerability?

Discourse is an open-source discussion platform. Prior to version 2.9.0.beta13, users can post chat messages of an unlimited length, which can cause a denial of service for other users when posting huge amounts of text. Users should upgrade to version 2.9.0.beta13, where a limit has been introduced. No known workarounds are available.

02Affected products

Vendor	Product	Versions
discourse	discourse	< 2.9.0.beta13

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-11-28T00:00:00.000Z
• Last modified: 2025-04-23T16:34:31.783Z

09References

• github.com — https://github.com/discourse/discourse/security/advisories/GHSA-mfh7-6cv6-qccc
• github.com — https://github.com/discourse/discourse/commit/3de765c89524a526ce611e11468d758a47…