CVE-2023-25167 — Discourse is an open source discussion platform

Discourse is an open source discussion platform. In affected versions a malicious user can cause a regular expression denial of service using a carefully crafted git URL. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to

01What is this vulnerability?

Discourse is an open source discussion platform. In affected versions a malicious user can cause a regular expression denial of service using a carefully crafted git URL. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. There are no known workarounds for this issue.

02Affected products

Vendor	Product	Versions
discourse	discourse	< 3.0.1, >= 3.1.0.beta, < 3.1.0.beta2

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: 2023-02-08T19:31:59.994Z
• Last modified: 2025-03-10T21:14:33.388Z

09References

• github.com — https://github.com/discourse/discourse/security/advisories/GHSA-4w55-w26q-r35w
• github.com — https://github.com/discourse/discourse/commit/ec4c30270887366dc28788bc4ab8a22a09…