CVE-2025-54801

Name of the Vulnerable Software and Affected Versions Fiber versions 2.52.8 and below

Description Fiber is an Express inspired web framework written in Go. 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 can result in a denial of service (DoS) due to memory exhaustion or server crash.

Recommendations Fiber version 2.52.9 or later should be used.