NULL pointer dereference in Microsoft Malware Protection Engine - CVE-2026-122194

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a null pointer dereference in Microsoft Defender when processing input delivered over a network. A remote attacker can trigger the flaw over a network, with user interaction required, to execute arbitrary code.

Affected software

How to mitigate CVE-2026-122194

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-122194
• https://www.microsoft.com/en-us/wdsi/defenderupdates

Related Security Bulletins

• NULL pointer dereference in Microsoft Malware Protection Engine