Discourse XSS via chat titles in v3.5.0 and earlier (fixed 3.5.1)
CVE-2025-58054 Published on October 1, 2025
Discourse is an open-source community discussion platform. Versions 3.5.0 and below are vulnerable to XSS attacks through parsing and rendering of chat channel titles and chat thread titles via the quote message functionality when using the rich text editor. This issue is fixed in version 3.5.1.
Vulnerability Analysis
CVE-2025-58054 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is a Basic XSS Vulnerability?
The software receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. This may allow such characters to be treated as control characters, which are executed client-side in the context of the user's session. Although this can be classified as an injection problem, the more pertinent issue is the improper conversion of such special characters to respective context-appropriate entities before displaying them to the user.
CVE-2025-58054 has been classified to as a Basic XSS vulnerability or weakness.
Products Associated with CVE-2025-58054
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Affected Versions
discourse Version < 3.5.1 is affected by CVE-2025-58054Exploit 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.