CVE-2026-97787

7.0High

Published 13 Oct 2026 · NVD status: Analyzed · AI triage by gemini-3.8-flash

7.0High

Attack vector: Local
Complexity: High
Privileges needed: Low
User interaction: None
Impact: Full C/I/A compromise
Weakness: CWE-362

Impact

Local authenticated attackers can elevate privileges to SYSTEM. They need prior local execution access on the target host or container.

Root cause

A race condition due to improper synchronization of shared resources in the Windows Container Isolation FS Filter Driver (unionfs.sys).

Affected systems

Versions not listed — check the vendor advisory.

CVSS v3.1 · CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Fix & remediation

Install the security update from Microsoft for unionfs.sys. No interim mitigation is documented in the advisory.

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

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NVD description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to elevate privileges locally.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97787PatchVendor Advisory

Source: nvd.nist.gov/vuln/detail/CVE-2026-97787