CVE-2026-59711

MediumCVSS 6.1/10Last modified Oct 25, 2026

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.

Metrics

CVSS 3.1 6.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Weakness enumeration

Affected software

No affected versions have been published.

Timeline

Published
Jul 6, 2026
Last modified
Oct 25, 2026
NVD status
Deferred

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CVE-2026-59711: Medium severity, CVSS 6.1 | Vulnix