CVE-2021-43794

Name: CVE-2021-43794
Creator: NVD / NIST
Published: 2021-12-01T20:15:08.727+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.02%

Last modified Jun 17, 2026

CVE-2021-43794 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. EPSS estimates a 1.02% chance of exploitation in the next 30 days.

Description

Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

1.02%

58.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-610

Affected Software

Vendor	Product	Versions
Discourse	Discourse	< 2.7.11

References

https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1Patch, Third Party Advisory
https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hpThird Party Advisory
https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1Patch, Third Party Advisory
https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hpThird Party Advisory

Timeline

Published: Dec 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43794?

How severe is CVE-2021-43794?

CVE-2021-43794 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43794?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43794?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST