CVE-2025-66630
Fiber insecurely fallsback in utils.UUIDv4() / utils.UUID() — predictable / zero‑UUID on crypto/rand failure
Description
Fiber is an Express inspired web framework written in Go. Before 2.52.11, on Go versions prior to 1.24, the underlying crypto/rand implementation can return an error if secure randomness cannot be obtained. Because no error is returned by the Fiber v2 UUID functions, application code may unknowingly rely on predictable, repeated, or low-entropy identifiers in security-critical pathways. This is especially impactful because many Fiber v2 middleware components (session middleware, CSRF, rate limiting, request-ID generation, etc.) default to using utils.UUIDv4(). This vulnerability is fixed in 2.52.11.
INFO
Published Date :
Feb. 9, 2026, 6:16 p.m.
Last Modified :
Feb. 9, 2026, 6:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-66630
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Fiber to version 2.52.11 or later.
- Verify secure randomness in critical security pathways.
- Review middleware configurations using UUID generation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66630.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66630 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66630
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66630 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66630 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Feb. 09, 2026
Action Type Old Value New Value Added Description Fiber is an Express inspired web framework written in Go. Before 2.52.11, on Go versions prior to 1.24, the underlying crypto/rand implementation can return an error if secure randomness cannot be obtained. Because no error is returned by the Fiber v2 UUID functions, application code may unknowingly rely on predictable, repeated, or low-entropy identifiers in security-critical pathways. This is especially impactful because many Fiber v2 middleware components (session middleware, CSRF, rate limiting, request-ID generation, etc.) default to using utils.UUIDv4(). This vulnerability is fixed in 2.52.11. Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-338 Added Reference https://github.com/gofiber/fiber/commit/eb874b6f6c5896b968d9b0ab2b56ac7052cb0ee1 Added Reference https://github.com/gofiber/fiber/releases/tag/v2.52.11 Added Reference https://github.com/gofiber/fiber/security/advisories/GHSA-68rr-p4fp-j59v