CVE-2026-20931

Windows Telephony Service Elevation of Privilege Vulnerability

At a glance

Severity: HIGH 8.0
EPSS: EPSS 0.84 % · percentile 58 (2026-10-27)
State: PUBLISHED
Published: 2026-01-13
Updated: 2026-07-30
Assigner: microsoft
NVD status: Modified

Description

External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 8.0	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	microsoft
CVSS 3.1	HIGH 8.0	CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	NVD · secure@microsoft.com (Secondary)

Weaknesses (CWE)

CWE-73

European references

ENISA EUVD · EUVD-2026-2123
GCVE · GCVE-0-2026-20931

CERT-FR advisories

CERTFR-2026-AVI-0044 — Multiples vulnérabilités dans Microsoft Windows · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:* < 10.0.14393.8783
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:* < 10.0.14393.8783
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* < 10.0.17763.8276
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* < 10.0.17763.8276
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:* < 10.0.19044.6809
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:* < 10.0.19045.6809
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:* < 10.0.22631.6491
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:* < 10.0.26100.7623
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:*:* < 10.0.26200.7623
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* < 10.0.14393.8783
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* < 10.0.17763.8276
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* < 10.0.20348.4648
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* < 10.0.25398.2092
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* < 10.0.26100.32230

Affected products

Product	Versions
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

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD