Discourse CVE-2025-22602: Arbitrary JS via Malicious Video Placeholder (No CSP)
CVE-2025-22602 Published on February 4, 2025
Stored DOM-based XSS (without CSP) via video placeholders in Discourse
Discourse is an open source platform for community discussion. In affected versions an attacker can execute arbitrary JavaScript on users' browsers by posting a malicious video placeholder html element. This issue only affects sites with CSP disabled. This problem has been patched in the latest version of Discourse. Users are advised to upgrade. Users unable to upgrade should enable CSP.
Vulnerability Analysis
CVE-2025-22602 is exploitable with network access, and does not require authorization privileges or user interaction. 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 a small impact on 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-2025-22602 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2025-22602
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Affected Versions
discourse:- Version stable: <= 3.3.3 is affected.
- Version beta: <= 3.4.0.beta3 is affected.
- Version tests-passed: <= 3.4.0.beta3 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.