Cross-site scripting in Discourse - CVE-2025-67723
Published: July 1, 2026
Vulnerability identifier: #VU136499
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-67723
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote user to perform cross-site scripting.
The vulnerability exists due to improper neutralization of input during web page generation in the discourse-math plugin KaTeX variant when rendering mathematical content. A remote user can submit specially crafted content to perform cross-site scripting.
Content Security Policy mitigates the impact, and user interaction is required to view the crafted content.
How to mitigate CVE-2025-67723
Install security update from vendor's website.