---
id: "CVE-2025-55653"
kind: "vulnerability"
aliases: ["CVE-2025-55653"]
title: "GPAC MP4Box: crafted MP4 file with zero denominator crashes process"
severity: "medium"
cvss: 5.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["gpac", "media-processing", "mp4box", "package", "self-hosted"]
not_affected_if: ["trusted-input-only"]
published_at: "2026-10-16T19:16:57+00:00"
first_seen_at: "2026-10-23T21:57:14+00:00"
updated_at: "2026-10-25T04:14:07+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-55653", "first_seen_at": "2026-10-23T21:57:14+00:00"}]
---

# GPAC MP4Box: crafted MP4 file with zero denominator crashes process

GPAC MP4Box v2.4 divides by zero in gf_parse_lfrac when an MP4 file contains a zero-denominator fraction string. The process terminates with SIGFPE, which is a denial of service and not code execution.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `MP4Box -version` and compare against the fixed release in the sources
- unknown whether the sources list a fixed version

## Fix

- Move MP4Box to a release newer than `v2.4` once the vendor ships a fix
- unknown whether the sources name a fixed version

## Timeline

- 2026-10-23T21:57:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-55653

## From the sources

GPAC MP4Box v2.4 was discovered to contain a floating point exception in the gf_parse_lfrac function (utils/error.c). Processing a crafted MP4 file containing a zero-denominator fraction string causes gf_parse_lfrac() to divide by zero, terminating the process with SIGFPE.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_