{"id":"CVE-2026-50159","summary":"Mermaid allows CSS injection applying to sibling elements of the diagram","details":"Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid is vulnerable to CSS injection via sibling combinator selectors generated from diagram-supplied class or id names. An attacker who can supply diagram text can inject arbitrary CSS into the rendered page, potentially altering the appearance or behavior of unrelated page elements. This issue is fixed in versions 10.9.8 and 11.16.1.","aliases":["GHSA-6x64-9x62-f2gx"],"modified":"2026-10-26T02:31:16.108636933Z","published":"2026-08-06T19:55:27.994Z","database_specific":{"cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50159.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.16.1"},{"type":"WEB","url":"https://github.com/mermaid-js/mermaid/releases/tag/v10.9.8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50159.json"},{"type":"ADVISORY","url":"https://github.com/mermaid-js/mermaid/security/advisories/GHSA-6x64-9x62-f2gx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50159"},{"type":"FIX","url":"https://github.com/mermaid-js/mermaid/commit/12d472c9ed43f94814b110da8d7a9ae6dd5266ed"},{"type":"FIX","url":"https://github.com/mermaid-js/mermaid/commit/7e83f1533318b307764d961906a73377266f4c5e"},{"type":"FIX","url":"https://github.com/mermaid-js/mermaid/pull/8022"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mermaid-js/mermaid","events":[{"introduced":"0"},{"fixed":"49c1a1c7d1faa995b07cc7224543bd0d9a7a9e70"},{"fixed":"7ecca0cd7f1658ef74f4e7e91f925724ef403bbf"},{"fixed":"12d472c9ed43f94814b110da8d7a9ae6dd5266ed"},{"fixed":"7e83f1533318b307764d961906a73377266f4c5e"}],"database_specific":{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"10.9.8"}],"source":"AFFECTED_FIELD"},{"strategy":"StringRangeExpression","range":[{"introduced":"11.0.0-alpha.1"},{"fixed":"11.16.1"}],"source":"AFFECTED_FIELD"},{"range":[{"fixed":"12d472c9ed43f94814b110da8d7a9ae6dd5266ed"}],"source":"REFERENCES_COMMIT"},{"range":[{"fixed":"7e83f1533318b307764d961906a73377266f4c5e"}],"source":"REFERENCES_COMMIT"},{"source":"REFERENCES_TAG","original_tag":"mermaid@11.16.1","range":[{"fixed":"7ecca0cd7f1658ef74f4e7e91f925724ef403bbf"}]},{"source":"REFERENCES_TAG","original_tag":"v10.9.8","range":[{"fixed":"49c1a1c7d1faa995b07cc7224543bd0d9a7a9e70"}]}]}}],"versions":["mermaid@11.16.0","@mermaid-js/tiny@11.16.0","@mermaid-js/parser@1.2.0","@mermaid-js/layout-elk@0.2.2","@mermaid-js/examples@1.3.0","v10.9.6","mermaid@11.15.0","@mermaid-js/mermaid-zenuml@0.2.3","@mermaid-js/parser@1.1.1","@mermaid-js/layout-tidy-tree@0.2.2","mermaid@11.14.0","@mermaid-js/tiny@11.14.0","@mermaid-js/parser@1.1.0","@mermaid-js/examples@1.2.0","v10.9.5","mermaid@11.13.0","@mermaid-js/tiny@11.13.0","@mermaid-js/parser@1.0.1","@mermaid-js/layout-elk@0.2.1","@mermaid-js/examples@1.1.0","mermaid@11.12.3","@mermaid-js/tiny@11.12.3","@mermaid-js/parser@1.0.0","@mermaid-js/layout-tidy-tree@0.2.1","mermaid@11.12.2","mermaid@11.12.1","@mermaid-js/tiny@11.12.1","v10.9.4","@mermaid-js/parser@0.6.3","mermaid@11.12.0","@mermaid-js/tiny@11.12.0","mermaid@11.11.0","@mermaid-js/tiny@11.11.0","@mermaid-js/layout-tidy-tree@0.2.0","@mermaid-js/layout-elk@0.2.0","mermaid@11.10.1","@mermaid-js/tiny@11.10.1","mermaid@11.10.0","@mermaid-js/tiny@11.10.0","@mermaid-js/mermaid-zenuml@0.2.2","@mermaid-js/layout-elk@0.1.9","v10.9.3","mermaid@11.8.1","@mermaid-js/tiny@11.8.1","@mermaid-js/parser@0.6.1","mermaid@11.8.0","@mermaid-js/tiny@11.8.0","@mermaid-js/parser@0.6.0","mermaid@11.7.0","@mermaid-js/tiny@11.7.0","@mermaid-js/parser@0.5.0","@mermaid-js/mermaid-zenuml@0.2.1","@mermaid-js/layout-elk@0.1.8","mermaid@11.6.0","@mermaid-js/parser@0.4.0","mermaid@11.5.0","@mermaid-js/layout-elk@0.1.7","mermaid@11.4.1","@mermaid-js/layout-elk@0.1.6","mermaid@11.4.0","mermaid@11.3.0","@mermaid-js/layout-elk@0.1.5","v10.9.1","v10.9.2","mermaid@11.2.1","@mermaid-js/layout-elk@0.1.4","mermaid@11.2.0","mermaid@11.1.1","mermaid@11.1.0","@mermaid-js/parser@0.3.0","@mermaid-js/layout-elk@0.1.3","@mermaid-js/layout-elk@0.1.2","mermaid@11.0.2","@mermaid-js/parser@0.2.0","@mermaid-js/layout-elk@0.1.1","mermaid@11.0.1","v11.0.0","v10.9.0","v10.7.0","v10.4.0","v10.3.0","v10.1.0","9.1.5","9.1.3","9.1.2","8.13.11","8.13.10","8.13.7","8.13.6","8.13.5","8.12.1","8.11.4","8.11.3","8.11.0-rc2","8.9.3","8.9.1","8.8.3","8.8.0","8.7.0","8.6.2","8.6.0","8.5.2","untagged-566ebfbf21141b604025","8.5.1","untagged-31c93788afe260d914bb","8.4.8","untagged-7651dabb407ecd5631ce","8.4.6","untagged-f43366252632a1a42020","8.4.4","8.2.0","8.3.0","8.2.6","8.2.5","8.2.4","8.2.3","8.2.2","8.1.0","8.2.1","7.0.5","7.0.3","7.0.2","7.0.0","6.0.0","0.5.7","0.5.6","0.5.5","0.5.4","0.5.3","0.5.2","0.5.1","0.5.0","0.4.0","0.3.5","0.3.4","0.3.3","0.3.2","0.3.1","0.3.0","0.2.16","0.2.15","0.2.14","0.2.13","0.2.8","0.2.7","0.2.6","0.2.5","0.2.4","0.2.3","0.2.2","0.2.1","0.2.0","0.1.1","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-50159.json"}}],"schema_version":"1.9.2","severity":[{"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"}]}