Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Lifecycle Timeline
4DescriptionGitHub Advisory
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the ai_bot_public_sharing_allowed_groups site setting.
AnalysisAI
Reflected cross-site scripting in Discourse AI conversation sharing allows unauthenticated attackers to inject malicious scripts through improperly sanitized conversation titles in the onebox rendering feature. An attacker can craft a malicious shared conversation link to execute arbitrary JavaScript in the context of other users' browsers, potentially stealing session tokens or performing unauthorized actions. …
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Vulnerability AssessmentAI
| Risk Assessment | Attackers can steal session cookies, redirect users to malicious sites, deface content, or perform actions on behalf of authenticated users. Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker injects a JavaScript payload into a vulnerable input field. When another user views the page, the script executes in their browser, stealing their session token. |
| Remediation | Encode all user-supplied output contextually (HTML, JS, URL). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 30 days: Identify affected systems running the SharedAiConversation model renders the conversation titl and apply vendor patches as part of regular patch cycle. …
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External POC / Exploit Code
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EUVD-2026-13192