CVE-2026-97792: Windows Container Isolation FS Filter Driver (unionfs.sys) Elevation of Privilege Vulnerability
Telemetry drift only. No threshold crossed and no authority ruling changed.
CVE record, CISA KEV and EPSS as of 2026-10-18.
CVEs like this one computed, by meaning
What to do now held facts and links
- Upgrade to the fixed version for your release line, or later: 10.0.22631.7652; 10.0.26100.9711; 10.0.26200.9711; 10.0.26300.9711; 10.0.20348.5761; 10.0.26100.33650 CVE record
- Record your decision, dated and frozen with today's evidence: patch by a date · mitigated by a compensating control · deferred · accepted the risk · not affected
- Check your version against the ranges this record publishes.
What it is stated by the CNA
Improper access control in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to elevate privileges locally.
- weakness
- CWE-732: Incorrect Permission Assignment for Critical Resource
- affected
- Microsoft Windows 11 version 23H2; Microsoft Windows 11 Version 23H2; Microsoft Windows 11 Version 24H2; Microsoft Windows 11 Version 25H2; Microsoft Windows 11 Version 26H2; Microsoft Windows Server 2022; Microsoft Windows Server 2025; Microsoft Windows Server 2025 (Server Core installation)
- published ranges
- microsoft windows 11 23h2 < 10.0.22631.7652; microsoft windows 11 24h2 < 10.0.26100.9711; microsoft windows 11 25h2 < 10.0.26200.9711; microsoft windows 11 26h2 < 10.0.26300.9711; and 2 more on the CVE page
- fixed in
- 10.0.22631.7652; 10.0.26100.9711; 10.0.26200.9711; 10.0.26300.9711; 10.0.20348.5761; 10.0.26100.33650
- severity
- 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- assigned by
- microsoft
- published
- 2026-10-13
check us msrc.microsoft.com
Exploit code held, dated
- exploit code
- None held in the PoC-in-GitHub feed. A public repository changes this brief.
What moved held, dated
| date | EPSS | event |
|---|---|---|
| 14 Oct 2026 | 0.00304 | |
| 17 Oct 2026 | 0.00298 |
2 observations held. A step marked with a scoring model moved because the measurement was replaced, not because the vulnerability changed.
Outside the record researched, cited
This section reads the record's references and adds cited findings from outside it. It needs an account. Everything above is held facts and is complete without it.
What would change this brief held, dated
- CISA KEV
- Not listed in the catalogue we hold. A listing changes this brief.
- exploit probability
- 0.00 on 2026-10-17 (FIRST's EPSS, a probability and not evidence of exploitation). Next band line: 10% (0.10). Crossing a line changes this brief.
- fix
- Held: 10.0.22631.7652; 10.0.26100.9711; 10.0.26200.9711; 10.0.26300.9711; 10.0.20348.5761; 10.0.26100.33650. A newer fix from the CNA or OSV changes this brief.
How to check this
Every value above is held with two dates: when it was true upstream (as_of) and when we recorded it (tx_from). Re-derive the exploit probability as it stood on any date:
SELECT value, source, source_version, as_of, tx_from
FROM volatile_valid_as_of('CVE-2026-97792', '2026-10-29T23:59:59.999999Z', now());