CVE-2026-27154CWE-79

Discourse has XSS when editing a malicious post

Low · published February 26, 2026

CVSS v4.0
1.3
EPSS
0%
Percentile
20.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
1.3 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U
EPSS
0.00293 · 20.8th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-02-26T21:20Z
EPSS history
Timeline
  • 26 FEB 21:20Z
    Discourse has XSS when editing a malicious post
    cvelistv5