Windows: Use after free in Connection Manager Service
Summary
A use-after-free weakness (CWE-416) in the Windows Connection Manager Service allows an authorized local user to elevate privileges. The attacker needs a local, low-privilege account and the attack is hard to reproduce reliably, so the risk is mainly on multi-user systems or after another compromise. The CVSS base score is 7.0 (High).
Affected
- Windows 10 Version 1607 (before 10.0.14393.9688)
- Windows 10 Version 1809 (before 10.0.17763.9487)
- Windows 10 Version 21H2 (before 10.0.19044.7846)
- Windows 10 Version 22H2 (before 10.0.19045.7846)
- Windows 11 Version 23H2 (before 10.0.22631.7711)
- Windows 11 Version 24H2 (before 10.0.26100.9974)
- Windows 11 Version 25H2 (before 10.0.26200.9974)
- Windows 11 Version 26H1 (before 10.0.28000.3501)
- Windows 11 Version 26H2 (before 10.0.26300.9974)
- Windows Server 2016 incl. Server Core (before 10.0.14393.9688)
- Windows Server 2019 incl. Server Core (before 10.0.17763.9487)
- Windows Server 2022 (before 10.0.20348.5870)
- Note: the Windows 10 22H2 and Windows 11 24H2 entries are taken from the CVE record; verify them against MSRC. Windows Server 2025 is not listed in the CVE record.
Fixed in
- Install the November 2026 cumulative update for each affected version (Microsoft fixed builds listed under Affected).
- Strix names KB5131090 for Windows Server 2022; this is unconfirmed and must be verified on MSRC.
Workaround
Unknown.
Exploitation
- No evidence of exploitation in the wild found; CISA SSVC lists exploitation as none and automatable as no.
- No public proof of concept found.
- Exploit maturity is rated Unproven in the CVSS vector.
Our recommendation
- Apply the November 2026 cumulative updates to all affected Windows 10, 11 and Server systems, starting with multi-user systems, terminal servers and shared workstations.
- Confirm installed builds against the MSRC advisory before and after patching.
- Check that your Windows 10 and Server builds are still supported, since unsupported builds may not receive a fix.
- Monitor for unusual local privilege escalation activity on endpoints.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Connection Manager 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
- CVE.org record CVE-2026-96042 www.cve.org
- Microsoft Security Update Guide (not retrieved) msrc.microsoft.com
- Strix aggregator CVE-2026-96042 www.strix.ai
- Rapid7 Patch Tuesday November 2026 www.rapid7.com
- Senserva KB5131090 senserva.com
- Qualys Patch Tuesday November 2026 review blog.qualys.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, 07:45.
Original description (NVD)
Use after free in Windows Connection Manager 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.
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