VulnerabilityModified
CVE-2026-20872
External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing over a network.
MEDIUM 6.5EPSS 20.1%
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 20.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
Description
External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing over a network.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- EPSS
- 20.06% probability · 97th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-73
- Affected
- microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows 11 25h2 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2022 23h2 · microsoft/windows server 2025
- Source
- secure@microsoft.com
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20872Vendor Advisory
- https://www.vicarius.io/vsociety/posts/cve-2026-20872-detection-script-spoofing-vulnerability-in-windows-ntlm
- https://www.vicarius.io/vsociety/posts/cve-2026-20872-mitigation-script-spoofing-vulnerability-in-windows-ntlm
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.