CVE-2026-32243
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
In Discourse, an attacker with the ability to create shared AI conversations can inject arbitrary HTML and JavaScript via crafted conversation titles. The payload executes in the browser of any user viewing the onebox preview, potentially allowing session hijacking or unauthorized actions on behalf of the victim.
Risk Assessment
An attacker can hijack a user's session or perform unauthorized actions when the victim clicks the malicious entry in the onebox preview.
Recommendation
Upgrade Discourse to version 2026.1.3, 2026.2.2, or 2026.3.0.
Original NVD description (English source)
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an attacker with the ability to create shared AI conversations could inject arbitrary HTML and JavaScript via crafted conversation titles. This payload would execute in the browser of any user viewing the onebox preview, potentially allowing session hijacking or unauthorized actions on behalf of the victim. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.