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CVE-2025-665659.3CriticalCWE-252

CVE-2025-66565: Fiber Utils UUIDv4 and UUID Silent Fallback to Predictable Values

gofiber · utils

Affected: gofiber utils · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days
43rd percentile
050100

Higher than 43% of scored CVEs

9.3CriticalCVSS 4.0
LowCrit.

DescriptionCVE.org

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 products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

  • gofiber · utilsgithub.com/gofiber/utils <= 1.2.0; github.com/gofiber/utils/v2 < 2.0.0-rc.4

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas
Exploitation
Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV
Not listed
Public check
No public nuclei template
Vendor
gofiber
Published
December 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-66565 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

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