Is CVE-2025-66565 actively exploited?

No active exploitation of CVE-2025-66565 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2025-66565 be exploited remotely?

Yes. CVE-2025-66565 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2025-66565?

CVE-2025-66565 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2025-66565

CRITICAL

CVE-2025-66565

CWE-252Published: December 9, 2025· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2025-66565 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.