Fiber Susceptible to Crash via `BodyParser` Due to Unvalidated Large Slice Index in Decoder

CVE Details

Basic Information

Title Fiber Susceptible to Crash via `BodyParser` Due to Unvalidated Large Slice Index in Decoder
Type cve
Published 2025-08-05T23:33:28.221Z
Modified 2025-08-05T23:33:28.221Z

Product Information

Vendor gofiber
Product fiber
Version < 2.52.9

CVSS Information

Base Score 8.7 (HIGH)
Attack Vector 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

Affected Products

  • gofiber fiber < 2.52.9

Additional Information

CWE List CWE-789
Source GitHub_M

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.

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