CVE-2026-40890 HIGH

CVE-2026-40890: github.com/gomarkdown/markdown: Out-of-bounds Read in SmartypantsRenderer

Vendor Gomarkdown
Product markdown
Weakness CWE-125
Published April 21, 2026
Last update April 21, 2026
View on NVD All CVEs

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 21, 2026 CVE published
April 21, 2026 Record updated