CVE-2026-83847: Microsoft Account heap buffer overflow privilege elevation

CVE-2026-83847 · Severity: high · CVSS 7.8 · Published 2026-10-13

Microsoft Account contains a heap buffer overflow vulnerability that allows an authorized local attacker to escalate their privileges on a Windows system. An attacker with valid credentials could exploit this flaw to gain elevated access and potentially control the entire system or access sensitive data.

Technologies: Microsoft Account. Vendors: Microsoft.

Quick answers

Is CVE-2026-83847 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-83847 being exploited in the wild.
How severe is CVE-2026-83847?
High severity, with a CVSS score of 7.8, published 13 October 2026.
Which products and versions are affected?
Microsoft Account.
Is there a fix for CVE-2026-83847?
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-2026-83847 attacked?
It is attacked with local access.
Am I affected by CVE-2026-83847?
Check whether you run Microsoft Account. 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 heap-based buffer overflow exists in Microsoft Account authentication components that can be triggered by an authenticated local attacker. The vulnerability requires valid user credentials and local system access but leads to privilege escalation. A memory corruption flaw of this type allows arbitrary code execution with elevated privileges.

Affected products

  • Microsoft Account

Timeline

  • 2026-10-13: disclosed

References

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