Out of Bounds Read in Go Markdown Library Affects Markdown Processing
CVE-2026-40890

7.5HIGH

Key Information:

Vendor

Gomarkdown

Status
Markdown
Vendor
CVE Published:
21 April 2026

What is CVE-2026-40890?

A vulnerability exists in the Go library for parsing and rendering Markdown text that could be exploited by processing malformed input. Specifically, if input contains a < character that is not accompanied by a > character within the remaining text, it may lead to an Out of Bounds read or cause a panic when using the SmartypantsRenderer. The issue has been addressed in recent updates, ensuring that users are protected against potential disruptions to Markdown processing.

Affected Version(s)

markdown < 759bbc3e32073c3bc4e25969c132fc520eda2778

References

https://github.com/gomarkdown/markdown/security/advisorie...
x_refsource_CONFIRM
https://github.com/gomarkdown/markdown/commit/759bbc3e320...
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.