CVE-2026-27740Discourse is an open-source discussion platform.
Updated under an hour ago ()
Does this affect you?
It affects discourse. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 6.1 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Weakness (CWE)
- CWE-79
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
discourse discourse discourse:discourse | from 2026.1.0 before 2026.1.2; from 2026.2.0 before 2026.2.1; 2026.3.0 | NVD |
References
- https://github.com/discourse/discourse/commit/44b84439df7e4424b2e7f216fd8fdd7dacff2227patch
- https://github.com/discourse/discourse/commit/8ae7cb2414d6918d7fc45e1fda7ffbb32912a975patch
- https://github.com/discourse/discourse/commit/ed70949f2c047196f33cfa94f2819df29c5d1e5fpatch
- https://github.com/discourse/discourse/security/advisories/GHSA-95hc-42c6-wvvrvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.