SARA / Free Tools / CVE / CVE-2023-23621

CVE-2023-23621 — Discourse is an open-source discussion platform

Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, a malicious user can cause a regular expression denial of service using a carefully crafted user agent. This issue is

CVSS
8.6 HIGH
EPSS
0.40% (top 40.00%)
CWE
CWE-1333
Published
2023-01-27T23:31:05.923Z
Last modified
2025-03-10T21:18:01.772Z
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

01What is this vulnerability?

Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, a malicious user can cause a regular expression denial of service using a carefully crafted user agent. This issue is patched in version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches…

02Affected products

VendorProductVersions
discoursediscourse< 3.0.1, = 3.1.0.beta1

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

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

09References

Want this in your SOAR or SIEM?
SARA's API returns EPSS, CVSS, KEV, and an analyst-grade summary in one call.
Read the API reference →