Discourse Graphviz Plugin XSS before 2026.3.0
CVE-2026-33395 Published on March 19, 2026
Discourse has stored click‑based XSS via Graphviz SVG javascript: links
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.
Vulnerability Analysis
CVE-2026-33395 can be exploited with network access, requires user interaction and a small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a XSS Vulnerability?
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
CVE-2026-33395 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-33395
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Affected Versions
discourse:- Version >= 2026.1.0-latest, < 2026.1.2 is affected.
- Version >= 2026.2.0-latest, < 2026.2.1 is affected.
- Version = 2026.3.0-latest is affected.