CVE-2026-56165
A heap-based buffer overflow in Microsoft Account lets an attacker run arbitrary code over the network. The flaw can be triggered without authentication or user interaction, giving the attacker full control of the affected system. No specific product versions are listed, so the vulnerability may affect any Microsoft Account implementation.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
Microsoft Account (no specific versions identified).
Real-world impact
An attacker can execute arbitrary code on the target machine, potentially taking full control, installing malware, or exfiltrating data.
Why this severity
The CVSS score of 9.8 reflects that the flaw can be exploited remotely over the network, requires no user interaction or privileges, and gives the attacker complete compromise of confidentiality, integrity, and availability.
What to do about it
No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.
No fix documented in sources
Timeline
- Jul 24, 2026 · 8d agoPublishedDisclosed and added to the National Vulnerability Database.
- Jul 30, 2026 · 2d agoAdvisory updatedThe NVD record was last revised.
How it’s attacked
References & advisories
- msrc.microsoft.com/update-guide/vulnerability/…vendor advisory