Vulnerabilities

Vulnerability · CVE-2026-20875

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

Published Jan 13, 2026 · catalog updated Jul 30, 2026 · Microsoft Windows Server 2008 R2 Service Pack 1

Last checked Oct 29, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-20875. EPSS is 1.54%. Act only if a listed version of Microsoft Windows Server 2008 R2 Service Pack 1 is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.54%
Remediation
Version ranges on file
Affected products
vendor Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.0 <6.1.7601.28117

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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.0 <6.1.7601.281176.1.7601.0 <6.1.7601.28117

How to fix CVE-2026-20875

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-20875. EPSS is 1.54%. Act only if a listed version of Microsoft Windows Server 2008 R2 Service Pack 1 is installed.

Which versions are affected?

Compare what you have installed with Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.0 <6.1.7601.28117 6.1.7601.0 <6.1.7601.28117. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 1.54%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 13, 2026 · EUVD

    Detected

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

  2. Jul 30, 2026 · EUVD

    Updated

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

Sources

  • CVE.orgVulnerability recordCVE-2026-20875

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-20875

    30-day exploitation probability 1.54%

    first.org
  • EUVDVulnerability recordEUVD-2026-2129

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

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgOct 29, 2026
  • FIRST EPSSOct 29, 2026
  • EUVDOct 29, 2026