{"id":"CVE-2026-59711","revision":"8ba8a9dbac264e45996cb868576a1830","records":[{"revision":"8ba8a9dbac264e45996cb868576a1830","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-59711","aliases":[],"title":"showdown - Cross-Site Scripting via Unescaped Metadata Title in completeHTMLDocument","description":"showdown contains a cross-site scripting vulnerability in metadata title handling that allows attackers to inject arbitrary HTML and JavaScript. When completeHTMLDocument option is enabled, unescaped less-than and greater-than characters in markdown frontmatter metadata are inserted directly into HTML title tags, enabling attackers to break out of the title context and execute malicious scripts in the rendered page.","state":0,"publishedAt":"2026-07-06T21:00:38.491+00:00","modifiedAt":"2026-07-07T14:06:55.895+00:00","affected":[{"ecosystem":"Vendor product","name":"showdown","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"showdown\",\n                    \"product\": \"showdown\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:npm/showdown\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThanOrEqual\": \"2.1.0\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","score":5.3,"severity":"MEDIUM"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1,"severity":"MEDIUM"}],"references":["https://github.com/showdownjs/showdown/issues/1047","https://github.com/showdownjs/showdown","https://www.vulncheck.com/advisories/showdown-cross-site-scripting-via-unescaped-metadata-title-in-completehtmldocument"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-59711","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-59711","identifiers":["CVE-2026-59711"]},"retained":false,"historicalAffected":[]}],"coverage":[]}