CyberSecBulletin
CVE-2026-20875NVD status: Analyzed

Windows 10 Version 1607: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2026-20875 is a high-severity NULL pointer dereference vulnerability in Windows 10 Version 1607 from Microsoft, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 10.0.14393.8783 as the first without the flaw, so updating Windows 10 Version 1607 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.54% chance of exploitation within 30 days, higher than 75% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Windows 10 Version 1607 to 10.0.14393.8783 or a later version.
  2. Update Windows 10 Version 1809 to 10.0.17763.8276 or a later version.
  3. Update Windows 10 Version 21H2 to 10.0.19044.6809 or a later version.
  4. Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
MicrosoftWindows 10 Version 160710.0.14393.0 up to, but not including, 10.0.14393.878310.0.14393.8783
MicrosoftWindows 10 Version 180910.0.17763.0 up to, but not including, 10.0.17763.827610.0.17763.8276
MicrosoftWindows 10 Version 21H210.0.19044.0 up to, but not including, 10.0.19044.680910.0.19044.6809
MicrosoftWindows 10 Version 22H210.0.19045.0 up to, but not including, 10.0.19045.680910.0.19045.6809
MicrosoftWindows 11 version 23H210.0.22631.0 up to, but not including, 10.0.22631.649110.0.22631.6491
MicrosoftWindows 11 Version 24H210.0.26100.0 up to, but not including, 10.0.26100.762310.0.26100.7623
MicrosoftWindows 11 Version 25H210.0.26200.0 up to, but not including, 10.0.26200.762310.0.26200.7623
MicrosoftWindows Server 2008 R2 Service Pack 16.1.7601.0 up to, but not including, 6.1.7601.281176.1.7601.28117
MicrosoftWindows Server 2008 R2 Service Pack 1 (Server Core installation)6.1.7601.0 up to, but not including, 6.1.7601.281176.1.7601.28117
MicrosoftWindows Server 2008 Service Pack 26.0.6003.0 up to, but not including, 6.0.6003.237176.0.6003.23717
MicrosoftWindows Server 2008 Service Pack 2 (Server Core installation)6.0.6003.0 up to, but not including, 6.0.6003.237176.0.6003.23717
MicrosoftWindows Server 20126.2.9200.0 up to, but not including, 6.2.9200.258686.2.9200.25868
MicrosoftWindows Server 2012 (Server Core installation)6.2.9200.0 up to, but not including, 6.2.9200.258686.2.9200.25868
MicrosoftWindows Server 2012 R26.3.9600.0 up to, but not including, 6.3.9600.229686.3.9600.22968
MicrosoftWindows Server 2012 R2 (Server Core installation)6.3.9600.0 up to, but not including, 6.3.9600.229686.3.9600.22968
MicrosoftWindows Server 201610.0.14393.0 up to, but not including, 10.0.14393.878310.0.14393.8783
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 up to, but not including, 10.0.14393.878310.0.14393.8783
MicrosoftWindows Server 201910.0.17763.0 up to, but not including, 10.0.17763.827610.0.17763.8276
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 up to, but not including, 10.0.17763.827610.0.17763.8276
MicrosoftWindows Server 202210.0.20348.0 up to, but not including, 10.0.20348.464810.0.20348.4648
MicrosoftWindows Server 2022, 23H2 Edition (Server Core installation)10.0.25398.0 up to, but not including, 10.0.25398.209210.0.25398.2092
MicrosoftWindows Server 202510.0.26100.0 up to, but not including, 10.0.26100.3223010.0.26100.32230
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 up to, but not including, 10.0.26100.3223010.0.26100.32230
MicrosoftWindows 10 1607before 10.0.14393.878310.0.14393.8783
MicrosoftWindows 10 1809before 10.0.17763.827610.0.17763.8276

Version data comes from the organisation that assigned the CVE; 7 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (microsoft.com).

Official description

Null pointer dereference in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

How developers prevent this class of flaw

  • For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
  • Select a programming language that is not susceptible to these issues.
  • Check the results of all functions that return a value and verify that the value is non-null before acting upon it.

More NULL Pointer Dereference vulnerabilities (CWE-476)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent NULL Pointer Dereference vulnerabilities

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