Vulnerability from bitnami_vulndb
Published
2026-03-27 07:09
Modified
2026-09-08 08:34
Summary
Discourse has Stored XSS in AI Triage Automation
Details

Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 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, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, temporarily disable AI triage automation scripts.

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "discourse",
        "purl": "pkg:bitnami/discourse"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2026.1.0"
            },
            {
              "fixed": "2026.1.2"
            },
            {
              "introduced": "2026.2.0"
            },
            {
              "fixed": "2026.2.1"
            },
            {
              "introduced": "2026.3.0"
            },
            {
              "fixed": "2026.3.0"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "type": "CVSS_V4"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27740"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Discourse is an open-source discussion platform. Versions prior to 2026.3.0, 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, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, temporarily disable AI triage automation scripts.",
  "id": "BIT-discourse-2026-27740",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-03-27T07:09:57.609Z",
  "references": [
    {
      "type": "FIX",
      "url": "https://github.com/discourse/discourse/commit/44b84439df7e4424b2e7f216fd8fdd7dacff2227"
    },
    {
      "type": "FIX",
      "url": "https://github.com/discourse/discourse/commit/8ae7cb2414d6918d7fc45e1fda7ffbb32912a975"
    },
    {
      "type": "FIX",
      "url": "https://github.com/discourse/discourse/commit/ed70949f2c047196f33cfa94f2819df29c5d1e5f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/discourse/discourse/security/advisories/GHSA-95hc-42c6-wvvr"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27740"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Discourse has Stored XSS in AI Triage Automation"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.