{"id":"GHSA-22g5-r2x5-97cx","summary":"showdown allows stored cross-site scripting through table header ID injection","details":"showdown contains a stored cross-site scripting vulnerability in the parseHeaders function of src/subParsers/makehtml/tables.js that fails to properly escape table header ID attributes. Attackers can inject arbitrary HTML and script-executing SVG elements through double-quote characters in markdown table headers, achieving stored XSS when untrusted markdown is rendered with the default github flavor configuration.","aliases":["CVE-2026-59710"],"modified":"2026-08-07T21:26:12.439408Z","published":"2026-07-07T00:30:59Z","database_specific":{"cwe_ids":["CWE-79"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-08-07T21:03:43Z","nvd_published_at":"2026-07-06T22:16:50Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59710"},{"type":"WEB","url":"https://github.com/showdownjs/showdown/issues/1046"},{"type":"WEB","url":"https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf"},{"type":"PACKAGE","url":"https://github.com/showdownjs/showdown"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection"}],"affected":[{"package":{"name":"showdown","ecosystem":"npm","purl":"pkg:npm/showdown"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"2.1.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-22g5-r2x5-97cx/GHSA-22g5-r2x5-97cx.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"CVSS_V4","score":"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"}]}