Medium severity · published Mar 20, 2026
CVE-2026-33411
Discourse's solved topic stream has potential stored XSS in topic title
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a potential stored XSS in topic titles for the solved posts stream. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DI
discourse · discourse
>= 2026.1.0-latest, < 2026.1.2; >= 2026.2.0-latest, < 2026.2.1; = 2026.3.0-latest · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33411
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33411
Mitigation
https://github.com/discourse/discourse/security/advisories/GHSA-j3mm-ghh2-83x2
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