CVE-2025-66630

CVE-2025-66630 is a critical-severity vulnerability in Gofiber Fiber with a CVSS 3.x base score of 9.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.

Key facts

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.

Frequently asked questions

What is CVE-2025-66630?
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.
How severe is CVE-2025-66630?
CVE-2025-66630 has a CVSS 3.x base score of 9.4, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2025-66630 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66630?
CVE-2025-66630 affects Gofiber Fiber. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66630?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-66630 have an EU (EUVD) identifier?
Yes. CVE-2025-66630 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207191.
When was CVE-2025-66630 published?
CVE-2025-66630 was published on 2026-02-09 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Gofiber Fiber

All CVEs affecting Gofiber Fiber →

Other CWE-338 vulnerabilities

Browse all CWE-338 vulnerabilities →