CVE-2026-36909: Aleksoid1978 MPC-BE NULL pointer dereference in AP4_TkhdAtom::GetTrackId

CVE-2026-36909 · Severity: info · CVSS 5.5 · Published 2026-07-01

MPC-BE is a popular open-source media player for Windows. A vulnerability was found where opening a specially crafted MP4 video file can cause the application to crash or stop responding. This issue primarily affects the reliability of the software and could be used to disrupt a user's ability to play media files.

Technologies: Aleksoid1978 MPC-BE. Vendors: Aleksoid1978.

Quick answers

Is CVE-2026-36909 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-36909 being exploited in the wild.
How severe is CVE-2026-36909?
Informational severity, with a CVSS score of 5.5, published 1 July 2026.
Which products and versions are affected?
Aleksoid1978 MPC-BE before commit 4341cb3.
Is there a fix for CVE-2026-36909?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-36909 attacked?
It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-36909?
Check whether you run Aleksoid1978 MPC-BE 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 the AP4_TkhdAtom::GetTrackId() function within the Bento4 library component used by Aleksoid1978 MPC-BE. The vulnerability is triggered when the application attempts to parse a malformed MP4 file containing specific atom structures. An attacker can exploit this by providing a crafted file to a user, which, when opened, causes the media player to crash (Denial of Service). The issue was addressed in commit 4341cb3.

Affected products

  • Aleksoid1978 MPC-BE before commit 4341cb3

Timeline

  • 2026-07-01: advisory: NVD publication date
  • 2026-07-01: disclosed

References

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