Discourse XSS via raw HTML in display_name before 2025.12.2/2026.1.1/2026.2.0
CVE-2026-27154 Published on February 26, 2026
Discourse has XSS when editing a malicious post
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` => true; and `prioritize_username_in_ux` => false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
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-2026-27154 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-27154
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Affected Versions
discourse:- Version < 2025.12.2 is affected.
- Version >= 2026.1.0-latest, < 2026.1.1 is affected.
- Version >= 2026.2.0-latest, < 2026.2.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.