# CVE-2025-66565

## Summary

- **CVE ID:** CVE-2025-66565
- **Severity:** CRITICAL
- **CVSS Score:** 9.3 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N)
- **CWE:** CWE-252, CWE-331, CWE-338
- **Published:** Dec 9, 2025
- **Last Modified:** Mar 13, 2026

## Description

Fiber Utils is a collection of common functions created for Fiber. In versions 2.0.0-rc.3 and below, when the system's cryptographic random number generator (crypto/rand) fails, both functions silently fall back to returning predictable UUID values, including the zero UUID "00000000-0000-0000-0000-000000000000". The vulnerability occurs through two related but distinct failure paths, both ultimately caused by crypto/rand.Read() failures, compromising the security of all Fiber applications using these functions for security-critical operations. This issue is fixed in version 2.0.0-rc.4.

## Affected Products

- gofiber — utils (github.com/gofiber/utils <= 1.2.0)
- gofiber — utils (github.com/gofiber/utils/v2 < 2.0.0-rc.4)

## References

- [CNA](https://github.com/gofiber/utils/security/advisories/GHSA-m98w-cqp3-qcqr)
- [CNA](https://github.com/gofiber/utils/commit/6c6cf047032b9c8dff43d29f990b4b10e9b02d47)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.47%
- **EPSS Percentile:** 38.9

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