Windows App Readiness Service: Tampering due to weak authentication
Summary
The Windows App Readiness Service in supported Windows 10, Windows 11 and Windows Server releases contains a weak authentication flaw (CWE-1390). An authorized local user with low privileges can tamper with the service, which affects integrity. The flaw cannot be exploited remotely and requires local access, so the main risk is privilege escalation or misuse on shared or multi-user systems.
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 (incl. Server Core): 10.0.14393.0 before 10.0.14393.9688 - Windows Server 2019 (incl. 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
- Fixed builds per the CNA record are listed in the affected ranges above (first build not affected). - Unverified: a secondary tracker cites 10.0.26100.33822 for Windows 11 24H2 and Windows Server 2025, which conflicts with the CNA range. Confirm the exact fixed builds and KB numbers in the MSRC advisory.
Workaround
Unknown. No vendor-documented workaround was found. Disabling the service is not a documented mitigation and may break Store apps, Edge sign-in and Outlook authentication, so test before any change.
Exploitation
- CISA SSVC: exploitation none, not automatable, partial technical impact. - Rapid7 (November 2026): Exploitation Less Likely, not publicly disclosed. - No reports of in-the-wild exploitation, public proof-of-concept code or CISA KEV listing found as of 11 November 2026.
Our recommendation
- Install the November 2026 security update on all affected Windows 10, Windows 11 and Windows Server systems, prioritizing shared and multi-user hosts and virtual desktop session hosts. - Include Windows 10 systems under Extended Security Updates. - Limit local low-privileged access on shared machines. - Verify the affected products and KB numbers in the MSRC advisory. - Monitor the CISA KEV catalogue and NVD for changes.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Tampering – Windows App Readiness Service
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-95944 msrc.microsoft.com
- CVE Record CVE-2026-95944 (CNA: Microsoft) www.cve.org
- Rapid7: Patch Tuesday review November 2026 www.rapid7.com
- Strix: CVE-2026-95944 (secondary, unverified product list) www.strix.ai
- BatCmd: Windows App Readiness service description batcmd.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 11 Nov 2026, 16:34.
Original description (NVD)
Weak authentication in Windows App Readiness Service allows an authorized attacker to perform tampering 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.
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