What is the CVSS score of CVE-2026-62726?

CVE-2026-62726 has a CVSS 3.1 base score of 7.0 (High). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.3%.

Which versions of Windows Telephony Service are affected by CVE-2026-62726?

A privilege escalation vulnerability in Windows Telephony Service (TAPI) allows authenticated local users to gain system administrator access across Windows infrastructure from Server 2012 through…. A patch is available.

How to fix or mitigate CVE-2026-62726?

Within 24 hours, inventory all affected Windows systems (Server 2012 through Windows 11 26H1, Windows Server 2022, and Windows Server 2025 builds) and identify those running or exposing TAPI services to evaluate exposure scope. Within 7 days, apply the Microsoft-released patch to critical infrastructure, high-value servers, and systems with elevated user access requirements as the priority tier. Within 30 days, complete patch deployment across all remaining affected Windows systems in your environment to eliminate the local privilege escalation attack surface.

Windows Telephony Service CVE-2026-62726

EUVD-2026-56640 HIGH

Use After Free (CWE-416)

2026-08-11 secure@microsoft.com

GHSA-3cp5-3rrc-p3m6

Denial Of Service Use After Free Memory Corruption Microsoft Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 23h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2025

7.0

CVSS 3.1 · Vendor: microsoft

Severity by source

Vendor (microsoft) PRIMARY

7.0 HIGH

AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

vuln.today AI

7.0 HIGH

Local access and low-privilege account required (AV:L, PR:L); high complexity reflects UAF heap-grooming requirements; full C/I/A justified by SYSTEM-level privilege escalation outcome.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Aug 11, 2026 - 20:24 vuln.today

Patch available

Aug 11, 2026 - 18:19 EUVD

CVE Published

Aug 11, 2026 - 17:18 nvd

HIGH 7.0

DescriptionCVE.org

Use after free in Windows Telephony Service allows an authorized attacker to elevate privileges locally.

AnalysisAI

Privilege escalation in Windows Telephony Service (TAPI) via a use-after-free memory corruption flaw enables a locally authenticated, low-privileged attacker to gain SYSTEM-level access on affected hosts. The vulnerability spans a broad range of Microsoft Windows versions from Server 2012 through Windows 11 26H1 and multiple Windows Server 2022/2025 builds, confirmed by Microsoft MSRC and catalogued under EUVD-2026-56640. No public exploit code or active exploitation has been identified at time of analysis, though the pervasive Windows deployment footprint makes patch deployment a meaningful operational priority.

Technical ContextAI

The Windows Telephony Application Programming Interface (TAPI) service provides telephony and voice-communication operations for legacy and enterprise applications on Windows. CWE-416 (Use After Free) describes a memory safety flaw where a program retains a pointer to a memory region after that region has been freed; when the freed memory is subsequently reallocated and controlled by an attacker, they can overwrite function pointers or object metadata to redirect execution. In the context of a privileged Windows service like TapiSrv, successful UAF exploitation can yield code execution at SYSTEM integrity level. The CVSS vector AV:L/AC:H is consistent with the class of exploitation technique involved - heap grooming, object spraying, or race-condition timing - which require local access and non-trivial effort to execute reliably. Affected CPE spans the full range from Windows 10 1607 (build 10.0.14393.x) through Windows 11 26H1 (build 10.0.28000.x) and Windows Server 2012 through 2025.

RemediationAI

Apply the vendor-released patch via Windows Update or the Microsoft Update Catalog; exact fixed build numbers per product version are confirmed in the EUVD-2026-56640 data and the Microsoft MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62726. For Windows Server 2012 and 2012 R2 - which are past mainstream support - verify that an active Extended Security Update (ESU) subscription is in place to receive this fix. Where immediate patching is not feasible, disabling or restricting the Windows Telephony Service (TapiSrv) is a viable compensating control for systems that do not rely on TAPI-dependent applications, though this will break any telephony or voice-integration software consuming the service. Additionally, restricting local interactive logon and Remote Desktop access to reduce the pool of low-privileged accounts that could satisfy the PR:L prerequisite narrows the exposure surface, but does not eliminate risk from insiders or threat actors who have already achieved a foothold. Prioritize patching on multi-user systems and shared infrastructure where unprivileged local logon is routinely available.