Microsoft Windows: Elevation of privilege in Windows Update Service
Summary
An untrusted search path in the Windows Update Service allows an authorized local attacker to elevate privileges. The attacker needs a foothold on the affected system with low privileges, and no user interaction is required. The impact on confidentiality, integrity and availability is rated high.
Affected
- Windows 11 23H2 before 10.0.22631.7652
- Windows 11 24H2 before 10.0.26100.9711
- Windows 11 25H2 before 10.0.26200.9711
- Windows 11 26H1 before 10.0.28000.3231
- Windows 11 26H2 before 10.0.26300.9711
- Windows Server 2025 (including Server Core) before 10.0.26100.33650
- Build numbers taken from the CVE record and aggregators; verify on the MSRC page.
Fixed in
- Windows 11 23H2: 10.0.22631.7652
- Windows 11 24H2: 10.0.26100.9711
- Windows 11 25H2: 10.0.26200.9711
- Windows 11 26H1: 10.0.28000.3231
- Windows 11 26H2: 10.0.26300.9711
- Windows Server 2025: 10.0.26100.33650
- Fixed builds for ARM64 variants and other editions: Unknown.
Workaround
Unknown.
Exploitation
- No evidence of exploitation in the wild found.
- CISA SSVC: exploitation none, automatable no.
- Not listed in CISA KEV.
- No public proof-of-concept found.
- EPSS score 0.00364.
Our recommendation
- Install the October 2026 security update on all affected Windows 11 and Windows Server 2025 systems, prioritising shared workstations, terminal and RDS servers.
- Confirm the build numbers on the MSRC affected-products table before rollout.
- Verify patch status across the fleet afterwards.
- Check that 23H2 machines are still within their support period.
- Re-check NVD and CISA KEV for changes to the exploitation status.
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Response Center: CVE-2026-70142 msrc.microsoft.com
- Strix: CVE-2026-70142 affected products www.strix.ai
- Vulners MSCVE: MS:CVE-2026-70142 vulners.com
- OpenCVE: CVE-2026-70142 app.opencve.io
- Vulners Rapid7: RAPID7:CVE-2026-70142 (EPSS) vulners.com
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 2 Nov 2026, 04:04.
Original description (NVD)
Untrusted search path in Windows Update Service allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.