CVE-2025-54801

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.

CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-789 CWE-789

Affected Products

Vendor	Product	Versions
gofiber	fiber	< 2.52.9

References

Advisories & Patches

https://github.com/gofiber/fiber/commit/e115c08b8f059a4a031b492aa9eef0712411853d https://github.com/gofiber/fiber/security/advisories/GHSA-qx2q-88mx-vhg7 https://github.com/gofiber/fiber/security/advisories/GHSA-qx2q-88mx-vhg7

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-54801? +

CVE-2025-54801 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-54801? +

CVE-2025-54801 affects products from gofiber, specifically: fiber. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-54801? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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