Discourse vulnerable to stored Cross-site Scripting via Katex in discourse-math plugin

{
  "id": "f2833552d8cc0bb40d49a0a4acc9650fc2cf65071d2418429937aba36f73e5d2",
  "url": "https://osv.dev/vulnerability/CVE-2025-67723",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Discourse vulnerable to stored Cross-site Scripting via Katex in discourse-math plugin",
    "summary": "Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have a content-security-policy-mitigated cross-site scriptinv vulnerability on the Discourse Math plugin when using its KaTeX variant. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, the Discourse Math plugin can be disabled, or the Mathjax provider can be used instead of KaTeX.",
    "evidence": "osv:CVE-2025-67723",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-67723",
      "aliases": [
        "BIT-discourse-2025-67723",
        "CVE-2025-67723",
        "GHSA-955h-m28g-5379"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/discourse/discourse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "75d61b40ee928a4620b16f5438ca886678fab00d"
                },
                {
                  "fixed": "f31b18139a7aadbc4a5f7e8e565a6f4376010c3a"
                },
                {
                  "introduced": "3e7317b3344cca6c6510a32cc4c5c0f540132ad9"
                },
                {
                  "last_affected": "3e7317b3344cca6c6510a32cc4c5c0f540132ad9"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
                    "range": [
                      {
                        "introduced": "2025.11.0"
                      },
                      {
                        "fixed": "2025.11.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:2025.12.0:*:*:*:stable:*:*:*",
                    "range": [
                      {
                        "introduced": "2025.12.0"
                      },
                      {
                        "last_affected": "2025.12.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2025.12.0",
            "v2025.11.1",
            "v2025.11.0",
            "v2025.12.0-latest"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-67723.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.584579871Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/67xxx/CVE-2025-67723.json",
        "https://github.com/discourse/discourse/security/advisories/GHSA-955h-m28g-5379",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-67723"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "3.5.4"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/67xxx/CVE-2025-67723.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-67723",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 500435,
  "published_at": "2026-01-28T18:21:35.379+00:00"
}