What’s Vulnerable › Vulnerabilities
CVE-2025-67723: Discourse vulnerable to stored Cross-site Scripting via Katex in discourse-math plugin
- Severity: medium (CVSS 5.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-01-28 · updated 2026-06-17
- Weakness: CWE-79
Description
Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have a content-security-policy-mitigated cross-site scriptinv vulnerability on the Discourse Math plugin when using its KaTeX variant. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, the Discourse Math plugin can be disabled, or the Mathjax provider can be used instead of KaTeX.
Affected products
- discourse: before 3.5.4; from 2025.11.0 before 2025.11.2; 2025.12.0 — fixed in 2025.11.2, 3.5.4
How to fix
Upgrade to a fixed version: discourse 2025.11.2, 3.5.4. Check the vendor advisory for mitigations.
References
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