CVE-2026-40890: Gomarkdown Markdown

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

The package `github.com/gomarkdown/markdown` is a Go library for parsing Markdown text and rendering as HTML. Processing a malformed input containing a < character that is not followed by a > character anywhere in the remaining text with a SmartypantsRenderer will lead to Out of Bounds read or a panic. This vulnerability is fixed with commit 759bbc3e32073c3bc4e25969c132fc520eda2778.

Affected products

• Gomarkdown Markdown: before 2026-04-10 (fixed in 2026-04-10)

Published 2026-04-21. Last modified 2026-06-17.