# CVE-2025-61729

## Summary

- **CVE ID:** CVE-2025-61729
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** N/A
- **Published:** Dec 2, 2025
- **Last Modified:** Sep 14, 2026

## Description

Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts that will be printed out. Furthermore, the error string is constructed by repeated string concatenation, leading to quadratic runtime. Therefore, a certificate provided by a malicious actor can result in excessive resource consumption.

## Affected Products

- Go standard library — crypto/x509 (0)
- Go standard library — crypto/x509 (1.25.0)

## References

- [CNA](https://go.dev/cl/725920)
- [CNA](https://go.dev/issue/76445)
- [CNA](https://groups.google.com/g/golang-announce/c/8FJoBkPddm4)
- [CNA](https://pkg.go.dev/vuln/GO-2025-4155)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.46%
- **EPSS Percentile:** 38.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._