VulnerabilityModified
CVE-2025-21371
Windows Telephony Service Remote Code Execution Vulnerability
HIGH 8.8EPSS 2.45%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.45%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Windows Telephony Service Remote Code Execution Vulnerability
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 2.45% probability · 83th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122
- Affected
- microsoft/windows 10 1507 · microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · 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-2025-21371Patch, Vendor Advisory
- https://www.vicarius.io/vsociety/posts/windows-telephony-service-remote-code-execution-vulnerability-detection-script
- https://www.vicarius.io/vsociety/posts/windows-telephony-service-remote-code-execution-vulnerability-mitigation-script
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.