VulnerabilityAnalyzed

CVE-2026-21249

External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.

LOW 3.3EPSS 11.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 11.1%, higher than 96% 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 locally.

CVSS 3.1: 3.3 LOWCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS: 11.14% probability · 96th 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 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-2026-21249Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.