CVE & CISA-KEV Catalog

CVE-2026-45657

CRITICALEPSS 96th pctl
9.8
CVSS v3
NVD

Description

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

CWE-122Heap-based Buffer OverflowCWE-416Use After Free

How to fix

Remediation Available
Windows 11 Version 23H2Windows
Install:KB5093998Microsoft
Windows 11 Version 24H2Windows
Install:KB5094126Microsoft
Windows 11 Version 25H2Windows
Install:KB5094126Microsoft
Windows 11 Version 26H1Windows
Install:KB5095051Microsoft
Windows 11 version 26H1Windows
Install:KB5095051Microsoft
Windows Server 2022Windows
Install:KB5094128Microsoft
Windows Server 2022 (Server Core installation)Windows
Install:KB5094128Microsoft
Windows Server 2025Windows
Install:KB5094125Microsoft
Windows Server 2025 (Server Core installation)Windows
Install:KB5094125Microsoft

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

15.48%probability of exploitation in 30 days
96thpercentile

Very high risk: more likely to be exploited than 96% of all known CVEs.

References

Vendor Advisory1

Related Vulnerabilities

Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2015-3113Critical9.8100%KEVFix
CVE-2024-26256High7.888%-Fix
CVE-2020-25687Medium5.987%-Fix
CVE-2009-3459High8.887%KEVFix
CVE-2021-21017High8.886%KEV-
CVE-2020-25683Medium5.986%-Fix

Common questions

How do I fix CVE-2026-45657?

Published advisories record a fix for 9 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-45657 being actively exploited?

Not that we know of. CVE-2026-45657 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 15.5% is the estimated probability that it will be exploited in the next 30 days. That is higher than 96% of all scored CVEs.

How severe is CVE-2026-45657?

CVE-2026-45657 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-45657 affect?

Published advisories record a fix for Windows 11 Version 23H2 (Windows), Windows 11 Version 24H2 (Windows), Windows 11 Version 25H2 (Windows), Windows 11 Version 26H1 (Windows), and 5 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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CVE-2026-45657 severity badge

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-23.