Quick answers
- Is CVE-2025-55639 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2025-55639 being exploited in the wild.
- How severe is CVE-2025-55639?
- Informational severity, with a CVSS score of 5.5, published 23 June 2026.
- Which products and versions are affected?
- Gpac MP4Box 2.4.
- Is there a fix for CVE-2025-55639?
- A patch was published on 2025-06-18: Fix committed to GPAC repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2025-55639 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2025-55639?
- Check whether you run Gpac MP4Box at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A NULL pointer dereference exists in GPAC MP4Box v2.4 within the gf_isom_add_track_kind() function located in isomedia/isom_write.c. The vulnerability is triggered when the function attempts to process a 'kind' parameter using gf_strdup() without first verifying if the pointer is NULL, specifically when handling crafted MP4 files containing MPEG-H Audio tracks. An attacker can exploit this by providing a malicious MP4 file, leading to a segmentation fault and application crash (Denial of Service). A fix has been committed to the GPAC repository which adds a null guard before the string duplication call.
Affected products
- GPAC MP4Box 2.4
Timeline
- 2025-06-18: disclosed: Issue reported on GitHub
- 2026-06-23: advisory: CVE published to NVD
- 2025-06-18: patched: Fix committed to GPAC repository