CVE-2026-85921
HIGH 8.2Double free in Windows Secure Kernel Mode allows an authorized attacker to elevate privileges locally.
ELEVATED IMPACT
Severe if exploited (CVSS 8.2), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 28th percentile
○ In CISA KEV
○ Catalogued PoC
Impact if exploited
8.2CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-415: : Double Free
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Windows 11 26h1 | < 10.0.28000.2956 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2956 |
All CVSS metrics
- HIGH 8.2 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 8.2 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85921 CVE record · microsoft · Updated 2026-10-14T23:09:32.182Z
NVD · CVE-2026-85921 · Updated 2026-09-29T19:24:48.280
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-77686 EUVD · EUVD-2026-77686