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CVE-2026-45657

CRITICAL 9.8 ALL-YEARS

Published 2026-06-09 · Last modified 2026-09-24 · microsoft · NVD: Analyzed

Use after free in Windows Kernel allows an unauthorized attacker to execute code over a network.

LIKELY TARGET

15.5% modeled chance of exploitation in the next 30 days (97th percentile). Prioritize remediation.

Exploitation likelihood

15.5%chance of exploitation in 30 days · 97th percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable yes

Impact if exploited

9.8CVSS 3.1 · CRITICAL · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓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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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Microsoft

Products Windows 11 Version 23h2 Windows 11 Version 24h2 Windows 11 Version 25h2 Windows 11 Version 26h1 Windows Server 2022 Windows Server 2025 Windows Server 2025 (Server Core Installation) Windows 11 23h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1

Weakness (CWE)

  • CWE-416: : Use After Free
  • CWE-122: : Heap-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

References and research data (JSON)

Known Affected Software Configurations

VendorProductVersion range
MicrosoftWindows 11 23h2< 10.0.22631.7219
MicrosoftWindows 11 23h2< 10.0.22631.7219
MicrosoftWindows 11 24h2< 10.0.26100.8655
MicrosoftWindows 11 24h2< 10.0.26100.8655
MicrosoftWindows 11 25h2< 10.0.26200.8655
MicrosoftWindows 11 25h2< 10.0.26200.8655
MicrosoftWindows 11 26h1< 10.0.28000.2269
MicrosoftWindows 11 26h1< 10.0.28000.2269
MicrosoftWindows Server 2022< 10.0.20348.5256
MicrosoftWindows Server 2025< 10.0.26100.32995

All CVSS metrics

  • CRITICAL 9.8 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
  • CRITICAL 9.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

Sources: NVD · CVE.org · All sources and attribution · EPSS