CVE-2026-33395

EUVD-2026-13402
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the discourse-graphviz plugin contains a stored cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious JavaScript code through DOT graph definitions. For instances with CSP disabled only. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable the graphviz plugin, upgrade to a patched version, or enable a content security policy.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.4 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
GitHub_MCNA
4.4 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
discoursediscourse
2026.1.0 ≤
𝑥
< 2026.1.2
discoursediscourse
2026.2.0 ≤
𝑥
< 2026.2.1
discoursediscourse
2026.3.0
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://github.com/discourse/discourse/commit/0471e68ed0b594bf386e068f228849244b880ef1
https://github.com/discourse/discourse/commit/0c861df8bea03dcc01b60da6cc7038e6c88de4ee
https://github.com/discourse/discourse/commit/472f9e1f7855307e489e9eaa6825d5335dfc08b5
https://github.com/discourse/discourse/security/advisories/GHSA-23c7-gq89-xm5v