Fiber is an Express-inspired web framework written in Go. Starting in version 2.52.6 and prior to version 2.52.7, fiber.Ctx.BodyParser can map flat data to nested slices using key[idx]value syntax, but when idx is negative, it causes a panic instead of returning an error stating it cannot process the data. Since this data is user-provided, this could lead to denial of service for anyone relying on this fiber.Ctx.BodyParser functionality. Version 2.52.7 fixes the issue.