CVE-2026-97787: high-severity vulnerability in Microsoft Windows 11 version 23H2
Windows Container Isolation FS Filter Driver (unionfs.sys) Elevation of Privilege Vulnerability
Published · Updated
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7epss 0.2%
exploitation probability
0.2%top 90% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Affected products
Microsoft · Windows 11 version 23H2Microsoft · Windows 11 Version 24H2Microsoft · Windows 11 Version 25H2Microsoft · Windows 11 version 26H1Microsoft · Windows 11 Version 26H2Microsoft · Windows Server 2022Microsoft · Windows Server 2025Microsoft · Windows Server 2025 (Server Core installation)Related CVEs — Microsoft Windows 11 version 23H2
In the same product, most dangerous first.
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