Kernel-level privilege escalation in Microsoft Windows affects widely used OS; impactful for enterprise security and should be widely communicated.
CVE-2026-85921
Windows Secure Kernel double-free allows local privilege escalation.
Is CVE-2026-85921 being exploited?
Not confirmed. CVE-2026-85921 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-85921?
CVE-2026-85921 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-85921?
Yes. A fix has been recorded for CVE-2026-85921. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-85921 affect?
CVE-2026-85921 affects Microsoft Windows Secure Kernel, Affected Windows versions (see MSRC advisory). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-85921?
Install Microsoft security update from MSRC and restrict local privileges immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can exploit a double-free in Secure Kernel to gain SYSTEM/kernel privileges, enabling full privilege escalation and persistence.
Patch when possible
- affected>= 10.0.28000.0 and < 10.0.28000.2956
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.