Discourse X before 2026.6.0 XSS via unescaped featured link
CVE-2026-55424 Published on July 9, 2026
Discourse: Topic featured link susceptible to stored XSS
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Vulnerability Analysis
CVE-2026-55424 is exploitable with network access. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
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-2026-55424 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-55424
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Affected Versions
discourse:- Version >= 2026.1.0-latest, < 2026.1.5 is affected.
- Version >= 2026.4.0-latest, < 2026.4.2 is affected.
- Version >= 2026.5.0-latest, < 2026.5.1 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.