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CVE-2025-54801

HIGHCVSS 8.7/10EPSS 0.33%

Last modified

CVE-2025-54801 is a high-severity vulnerability rated 8.7/10 on the CVSS scale. Fiber is an Express inspired web framework written in Go. In versions 2.52.8 and below, when using Fiber's Ctx.BodyParser to parse form data containing a large numeric key that represents a slice index (e.g., test.18446744073704), the application crashes due to an out-of-bounds slice allocation in the underlying schema decoder. EPSS estimates a 0.33% chance of exploitation in the next 30 days.

Description

Fiber is an Express inspired web framework written in Go. In versions 2.52.8 and below, when using Fiber's Ctx.BodyParser to parse form data containing a large numeric key that represents a slice index (e.g., test.18446744073704), the application crashes due to an out-of-bounds slice allocation in the underlying schema decoder. The root cause is that the decoder attempts to allocate a slice of length idx + 1 without validating whether the index is within a safe or reasonable range. If the idx is excessively large, this leads to an integer overflow or memory exhaustion, causing a panic or crash. This is fixed in version 2.52.9.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0
8.7/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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

EPSS Probability
0.33%

24.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
GofiberFiber< 2.52.9

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-54801?
Fiber is an Express inspired web framework written in Go. In versions 2.52.8 and below, when using Fiber's Ctx.BodyParser to parse form data containing a large numeric key that represents a slice index (e.g., test.18446744073704), the application crashes due to an out-of-bounds slice allocation in the underlying schema decoder. The root cause is that the decoder attempts to allocate a slice of length idx + 1 without validating whether the index is within a safe or reasonable range. If the idx is excessively large, this leads to an integer overflow or memory exhaustion, causing a panic or crash. This is fixed in version 2.52.9.
How severe is CVE-2025-54801?
CVE-2025-54801 has a CVSS score of 8.7/10 (HIGH severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.
How do I fix CVE-2025-54801?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-54801?

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Source: NVD / NIST