A AegiFlow
MEDIUMCVSS 5.3EPSS 0.2%

CVE-2026-59711

CVE-2026-59711 updated by NVD

Published
2026-07-06
Modified
2026-10-27
EPSS percentile
9%
Sources
github-advisory, nvd

Summary

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.

Affected packages

EcosystemPackageAffected versionsFixed versions
npmshowdown——

Remediation: No patched version is listed by GitHub.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.