Microsoft Windows Task Scheduler: Privilege escalation via link following

Summary

Windows Task Scheduler does not properly resolve links before accessing files (CWE-59, link following). An authorized local attacker can abuse this to elevate privileges. The CVSS vector rates the impact on confidentiality, integrity and availability as high, but exploitation requires high attack complexity and a local low-privileged foothold, for example after phishing, on a shared PC or on a terminal server.

Affected

• Windows 10 Version 1607 (10.0.14393.0 before 10.0.14393.9688)
• Windows 10 Version 1809 (10.0.17763.0 before 10.0.17763.9487)
• Windows 10 Version 21H2 (10.0.19044.0 before 10.0.19044.7846)
• Windows 10 Version 22H2 (10.0.19045.0 before 10.0.19045.7846)
• Windows 11 version 23H2 (10.0.22631.0 before 10.0.22631.7711)
• Windows 11 Version 24H2 (10.0.26100.0 before 10.0.26100.9974)
• Windows 11 Version 25H2 (10.0.26200.0 before 10.0.26200.9974)
• Windows 11 version 26H1 (10.0.28000.0 before 10.0.28000.3501)
• Windows 11 Version 26H2 (10.0.26300.0 before 10.0.26300.9974)
• Windows Server 2016, including Server Core (10.0.14393.0 before 10.0.14393.9688)
• Windows Server 2019, including Server Core (10.0.17763.0 before 10.0.17763.9487)
• Windows Server 2022 (10.0.20348.0 before 10.0.20348.5870)

Fixed in

• Windows 10 1607 and Server 2016: 10.0.14393.9688 or later
• Windows 10 1809 and Server 2019: 10.0.17763.9487 or later
• Windows 10 21H2: 10.0.19044.7846 or later
• Windows 10 22H2: 10.0.19045.7846 or later
• Windows 11 23H2: 10.0.22631.7711 or later
• Windows 11 24H2: 10.0.26100.9974 or later
• Windows 11 25H2: 10.0.26200.9974 or later
• Windows 11 26H1: 10.0.28000.3501 or later
• Windows 11 26H2: 10.0.26300.9974 or later
• Windows Server 2022: 10.0.20348.5870 or later
• KB numbers: Unknown.

Workaround

• Unknown. No vendor workaround identified.
• Until patched, limit local logon rights on shared and terminal servers (general hardening advice, not a vendor recommendation).

Exploitation

• No known exploitation at publication.
• No public proof of concept found.
• CISA SSVC: exploitation none, automatable no, technical impact total.

Our recommendation

• Install the November 2026 Windows security update on all affected systems, starting with shared PCs, terminal servers and administrator workstations.
• Confirm the exact builds and KB numbers in the MSRC Security Update Guide.
• Review scheduled tasks that run as SYSTEM or other privileged accounts.
• Check that all affected Windows versions are still supported by Microsoft.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-122174 msrc.microsoft.com
• CVE Record CVE-2026-122174 (CVE.org) www.cve.org
• Strix CVE-2026-122174 (third-party, unverified builds) www.strix.ai
• MITRE ATT&CK T1053.005 Scheduled Task/Job: Scheduled Task attack.mitre.org

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 08:21.