node-mermaid — security advisory

{
  "id": "1333f07ef4e4581ba812a693439be58a6c14694979e12cc690f127c00b87f457",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-41159",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-41159",
    "summary": "Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.6 and 11.15.0, Mermaid's default configuration allows injecting CSS that applies outside of the Mermaid diagram via the fontFamily, themeCSS, and altFontFamily configuration options. The injected CSS exploits stylis's & (scope reference) handling. :not(&) escapes the #mermaid-xxx automatic scoping, applying styles to all page elements. Global at-rules (@font-face, @keyframes, @counter-style) are also injectable as stylis hoists them to top level. This allows page defacement and DOM attribute exfiltration via CSS :has() selectors. This vulnerability is fixed in 10.9.6 and 11.15.0.",
    "evidence": "osv:UBUNTU-CVE-2026-41159",
    "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-2026-41159",
      "aliases": [
        "UBUNTU-CVE-2026-41159"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L"
        },
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        },
        {
          "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-2026-41159.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-2026-41159.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "node-mermaid",
                "binary_version": "9.2.2+~2.0.0-2"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:55:43.029302934Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-41159"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-41159",
        "https://www.cve.org/CVERecord?id=CVE-2026-41159",
        "https://github.com/mermaid-js/mermaid/security/advisories/GHSA-87f9-hvmw-gh4p",
        "https://github.com/mermaid-js/mermaid/commit/64769738d5b59211e1decb471ffbaca8afec51aa",
        "https://github.com/mermaid-js/mermaid/commit/a9d9f0d8eb790349121508688cd338253fd80d76",
        "https://github.com/mermaid-js/mermaid/commit/64769738d5b59211e1decb471ffbaca8afec51aahttps://github.com/mermaid-js/mermaid/commit/a9d9f0d8eb790349121508688cd338253fd80d76",
        "https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.15.0",
        "https://github.com/mermaid-js/mermaid/releases/tag/v10.9.6"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-41159",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 353986,
  "published_at": "2026-05-29T15:16:00+00:00"
}