{"cve":"CVE-2026-71437","nvd":{"published":"2026-08-06T22:18:30.713","modified":"2026-10-24T15:10:00.190","status":"Awaiting Analysis","description":"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.","cvss_v4":{"vector":"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","score":6.5},"cvss_v3":null,"cwes":["CWE-1321"],"references":["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","https://github.com/mermaid-js/mermaid/security/advisories/GHSA-3rrr-jr9j-h3q3","https://github.com/mermaid-js/mermaid/security/advisories/GHSA-3rrr-jr9j-h3q3"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-71437","score":0.00503,"percentile":0.42766,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-3rrr-jr9j-h3q3","url":"https://osv.dev/vulnerability/GHSA-3rrr-jr9j-h3q3","summary":"Mermaid Architecture diagrams are vulnerable to prototype pollution","modified":"2026-09-10T03:51:12.960083678Z","packages":[{"ecosystem":"npm","name":"mermaid","purl":"pkg:npm/mermaid","ranges":[">=11.5.0 <11.16.1"],"fixed":["11.16.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}