What is CVE-2026-40890?

CVE-2026-40890 is a high-severity vulnerability in Gomarkdown Markdown, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-04-21.

How severe is CVE-2026-40890?

High severity. CVSS v3 base score is 7.5 out of 10.

Out-of-bounds Read in Gomarkdown Markdown

CVE-2026-40890

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…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (22.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Gomarkdown Markdown — versions < 759bbc3e32073c3bc4e25969c132fc520eda2778

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

https://github.com/gomarkdown/markdown/security/advisories/GHSA-77fj-vx54-gvh7 (x_refsource_CONFIRM)
https://github.com/gomarkdown/markdown/commit/759bbc3e32073c3bc4e25969c132fc520eda2778 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-40890?: CVE-2026-40890 is a high-severity vulnerability in Gomarkdown Markdown, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-04-21.
How severe is CVE-2026-40890?: High severity. CVSS v3 base score is 7.5 out of 10.