CVE-2026-20931
External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.84%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.
- CVSS 3.1
- 8.0 HIGHCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.84% probability · 58th percentile
- Public exploits
- None in Exploit-DB
- 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
EPSS 0.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20931Vendor Advisory
- https://www.vicarius.io/vsociety/posts/cve-2026-20931-detection-script-elevation-of-privilege-vulnerability-in-windows-telephony-service
- https://www.vicarius.io/vsociety/posts/cve-2026-20931-mitigation-script-elevation-of-privilege-vulnerability-in-windows-telephony-service
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.