Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a cross-site scripting vulnerability that arises because the system trusts the raw output from an AI Large Language Model (LLM) and renders it using htmlSafe in the Review Queue interface without adequate sanitization. A malicious attacker can use valid Prompt Injection techniques to force the AI to return a malicious payload (e.g., tags). When a Staff member (Admin/Moderator) views the flagged post in the Review Queue, the payload executes. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, temporarily disable AI triage automation scripts.
References
Configurations
Configuration 1 (hide)
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History
25 Mar 2026, 00:58
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| Summary |
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| References | () https://github.com/discourse/discourse/commit/44b84439df7e4424b2e7f216fd8fdd7dacff2227 - Patch | |
| References | () https://github.com/discourse/discourse/commit/8ae7cb2414d6918d7fc45e1fda7ffbb32912a975 - Patch | |
| References | () https://github.com/discourse/discourse/commit/ed70949f2c047196f33cfa94f2819df29c5d1e5f - Patch | |
| References | () https://github.com/discourse/discourse/security/advisories/GHSA-95hc-42c6-wvvr - Vendor Advisory | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 6.1 |
| First Time |
Discourse
Discourse discourse |
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| CPE | cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:* cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* |
19 Mar 2026, 21:17
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| New CVE |
Information
Published : 2026-03-19 21:17
Updated : 2026-03-25 00:58
NVD link : CVE-2026-27740
Mitre link : CVE-2026-27740
CVE.ORG link : CVE-2026-27740
JSON object : View
Products Affected
discourse
- discourse
CWE
CWE-79
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
