What is CVE-2021-41140?

CVE-2021-41140 is a medium-severity vulnerability in Discourse Discourse-Reactions, classified under Exposure of Resource to Wrong Sphere. CVSS score: 5.3/10. Published 2021-10-19.

How severe is CVE-2021-41140?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Information disclosure in Discourse Discourse-Reactions

CVE-2021-41140

Discourse-reactions is a plugin for the Discourse platform that allows user to add their reactions to the post. In affected versions reactions given by user to secure topics and private messages are visible. This issue is patched in version 0.2 of discourse-reaction. Users who are unable to update are advised to disable the Discourse-reactions plugin in admin panel.

Published 2021-10-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (59.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Discourse Discourse-Reactions — versions < 0.2
Discourse Reactions

Weakness classification (CWE)

References

github.com/discourse/discourse-reactions/security/advisories/GHSA-9358-hwg5-jrmh (Third Party Advisory)
github.com/discourse/discourse-reactions/commit/213d90b82fd15c4186ebc290fee1881… (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-41140?: CVE-2021-41140 is a medium-severity vulnerability in Discourse Discourse-Reactions, classified under Exposure of Resource to Wrong Sphere. CVSS score: 5.3/10. Published 2021-10-19.
How severe is CVE-2021-41140?: Medium severity. CVSS v3 base score is 5.3 out of 10.