{"cve":"CVE-2026-59710","nvd":{"published":"2026-07-06T22:16:50.977","modified":"2026-07-07T13:57:49.473","status":"Deferred","description":"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.","cvss_v4":{"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},"cvss_v3":{"version":"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},"cwes":["CWE-79"],"references":["https://github.com/showdownjs/showdown","https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf","https://github.com/showdownjs/showdown/issues/1046","https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection","https://github.com/showdownjs/showdown/issues/1046"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:42:16.820116992+00:00"},"epss":{"cve":"CVE-2026-59710","score":0.00338,"percentile":0.27242,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-22g5-r2x5-97cx","url":"https://osv.dev/vulnerability/GHSA-22g5-r2x5-97cx","summary":"showdown allows stored cross-site scripting through table header ID injection","modified":"2026-09-10T03:51:09.845674087Z","packages":[{"ecosystem":"npm","name":"showdown","purl":"pkg:npm/showdown","ranges":["<=2.1.0"],"fixed":[]}]}],"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."]}