NULL Pointer DereferenceWeakness · CWE-476

CVE-2026-36909

MEDIUM · 6.2 CVSS v3.1 Published 2026-07-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
67/100
Remediation priority · Elevated
No privileges Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A NULL pointer dereference in the AP4_TkhdAtom::GetTrackId() function of Aleksoid1978 MPC-BE before commit 4341cb3 allows attackers to cause a Denial of Service (DoS) via a crafted MP4 file.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A NULL pointer dereference vulnerability exists in the AP4_TkhdAtom::GetTrackId() function of the MPC-BE media player. When parsing a specially crafted MP4 file, the code attempts to access a NULL pointer, causing the application to crash and result in a Denial of Service.

MitigationUpdate MPC-BE to the version containing commit 4341cb3 or later. Until an official patch is available, exercise caution when opening MP4 files from untrusted sources, as malformed track header (tkhd) atoms can trigger the NULL dereference.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify MPC-BE is installed
    Search for the mpc-be.exe file in common installation directories such as C:\Program Files\MPC-BE or C:\Program Files (x86)\MPC-BE, or use the Start menu search to locate MPC-BE.
    Affected if MPC-BE executable is found on the system
  2. Determine MPC-BE version
    Right-click on mpc-be.exe, select Properties, then go to the Details tab to view the Product version, or right-click MPC-BE in the Start menu and check Properties.
    Affected if Version cannot be determined or is older than the fixed version
  3. Compare version to fixed reference
    The vulnerability was fixed in the version containing commit 4341cb3. Compare your installed version against this reference point. If your version predates this commit, it contains the vulnerability.
    Affected if Installed version is older than the version containing commit 4341cb3
  4. Confirm MP4 file handling is possible
    Verify that MPC-BE has the capability to parse MP4 files by checking file associations or simply by attempting to play a standard MP4 file. The flaw triggers during MP4 parsing.
    Affected if MPC-BE can open and parse MP4 files

A system is affected if MPC-BE is installed with a version that predates the commit 4341cb3 fix and the application is used to open MP4 files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update MPC-BE to the version containing commit 4341cb3 or later. Until an official patch is available, exercise caution when opening MP4 files from untrusted sources, as malformed track header (tkhd) atoms can trigger the NULL dereference.

Recommended fix Moderate confidence

Upgrade to the MPC-BE release that includes commit 4341cb3 or later (check GitHub releases for the specific version number)

  1. 1. Identify the current MPC-BE version in use by checking About/Help in the application
  2. 2. Navigate to the official MPC-BE GitHub repository at github.com/Aleksoid1978/MPC-BE
  3. 3. Review the commit history to locate commit 4341cb3 and determine which release version includes this fix
  4. 4. Download and install the release version that includes commit 4341cb3 or a later stable release
  5. 5. Verify the installation by checking the version number in the application
  6. 6. Test playback of MP4 files to confirm the vulnerability is remediated
Caveat Review release notes for any breaking changes between your current version and the fixed version before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-36909 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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