node-mermaid — security advisory

{
  "id": "1c040bb2b2be296d82cf7ae1877153c1b0f4c59248b25cb234933411d5694892",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-71437",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-71437",
    "summary": "Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 11.5.0 until 11.16.1, Mermaid Architecture Diagrams are vulnerable to prototype pollution when a diagram defines a group with an id of __proto__. Because the group id is used directly as an object property key without validation, an attacker who can supply diagram text can pollute Object.prototype, potentially affecting the behavior of the embedding application. This issue is fixed in version 11.16.1.",
    "evidence": "osv:UBUNTU-CVE-2026-71437",
    "products": [
      {
        "name": {
          "value": "node-mermaid",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "8.7.0+ds+~cs27.17.17-3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "8.13.3+ds+~cs26.13.21-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "8.13.3+ds+~cs26.13.21-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "8.13.8+~cs10.4.16-1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "node-mermaid",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "9.2.2+~2.0.0-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "9.2.2+~2.0.0-2",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-71437",
      "aliases": [
        "UBUNTU-CVE-2026-71437"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "node-mermaid",
            "purl": "pkg:deb/ubuntu/node-mermaid?arch=source&distro=jammy",
            "ecosystem": "Ubuntu:22.04:LTS"
          },
          "versions": [
            "8.7.0+ds+~cs27.17.17-3",
            "8.13.3+ds+~cs26.13.21-1",
            "8.13.3+ds+~cs26.13.21-2",
            "8.13.8+~cs10.4.16-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71437.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-mermaid",
                "binary_version": "8.13.8+~cs10.4.16-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "node-mermaid",
            "purl": "pkg:deb/ubuntu/node-mermaid?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "9.2.2+~2.0.0-1",
            "9.2.2+~2.0.0-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71437.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-mermaid",
                "binary_version": "9.2.2+~2.0.0-2"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:59:33.089962136Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-71437"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-71437",
        "https://www.cve.org/CVERecord?id=CVE-2026-71437",
        "https://github.com/mermaid-js/mermaid/security/advisories/GHSA-3rrr-jr9j-h3q3",
        "https://github.com/mermaid-js/mermaid/commit/99af3fc35ef0a9a9c8c6314521344d67523ddccf",
        "https://github.com/mermaid-js/mermaid/pull/8022",
        "https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.16.1"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-71437",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 359683,
  "published_at": "2026-08-06T22:18:00+00:00"
}