CVE-2026-20931Windows Telephony Service Elevation of Privilege Vulnerability
- 8.0HighCVSS base score
- 0.84%Exploitation in 30 daysEPSS · top 41% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.
Timeline
ID reserved
By microsoft
- 40 days later
· 40 days later
Published
- 7 months later
· 7 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoftCNA (assigner) | 3.1 | High8.0 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
| NVDNVD · Modified | 3.1 | High8.0 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.84% · top 41% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.0.
Affected products
Microsoft · Windows 10 Version 1607
- affected 10.0.14393.0 – < 10.0.14393.8783
Microsoft · Windows 10 Version 1809
- affected 10.0.17763.0 – < 10.0.17763.8276
Microsoft · Windows 10 Version 21H2
- affected 10.0.19044.0 – < 10.0.19044.6809
Microsoft · Windows 10 Version 22H2
- affected 10.0.19045.0 – < 10.0.19045.6809
Microsoft · Windows 11 version 23H2
- affected 10.0.22631.0 – < 10.0.22631.6491
Microsoft · Windows 11 Version 23H2
- affected 10.0.22631.0 – < 10.0.22631.6491
Microsoft · Windows 11 Version 24H2
- affected 10.0.26100.0 – < 10.0.26100.7623
Microsoft · Windows 11 Version 25H2
- affected 10.0.26200.0 – < 10.0.26200.7623
Microsoft · Windows Server 2008 R2 Service Pack 1
- affected 6.1.7601.0 – < 6.1.7601.28117
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)
- affected 6.1.7601.0 – < 6.1.7601.28117
Microsoft · Windows Server 2008 Service Pack 2
- affected 6.0.6003.0 – < 6.0.6003.23717
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)
- affected 6.0.6003.0 – < 6.0.6003.23717
Microsoft · Windows Server 2012
- affected 6.2.9200.0 – < 6.2.9200.25868
Microsoft · Windows Server 2012 (Server Core installation)
- affected 6.2.9200.0 – < 6.2.9200.25868
Microsoft · Windows Server 2012 R2
- affected 6.3.9600.0 – < 6.3.9600.22968
Microsoft · Windows Server 2012 R2 (Server Core installation)
- affected 6.3.9600.0 – < 6.3.9600.22968
Microsoft · Windows Server 2016
- affected 10.0.14393.0 – < 10.0.14393.8783
Microsoft · Windows Server 2016 (Server Core installation)
- affected 10.0.14393.0 – < 10.0.14393.8783
Microsoft · Windows Server 2019
- affected 10.0.17763.0 – < 10.0.17763.8276
Microsoft · Windows Server 2019 (Server Core installation)
- affected 10.0.17763.0 – < 10.0.17763.8276
Microsoft · Windows Server 2022
- affected 10.0.20348.0 – < 10.0.20348.4648
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)
- affected 10.0.25398.0 – < 10.0.25398.2092
Microsoft · Windows Server 2025
- affected 10.0.26100.0 – < 10.0.26100.32230
Microsoft · Windows Server 2025 (Server Core installation)
- affected 10.0.26100.0 – < 10.0.26100.32230
References
References3
- Windows Telephony Service Elevation of Privilege Vulnerability (opens in a new tab)vendor-advisorypatch
- https://www.vicarius.io/vsociety/posts/cve-2026-20931-detection-script-elevation-of-privilege-vulnerability-in-windows-telephony-service (opens in a new tab)
- https://www.vicarius.io/vsociety/posts/cve-2026-20931-mitigation-script-elevation-of-privilege-vulnerability-in-windows-telephony-service (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-2123 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20931)Record last updated .