Microsoft Windows Credential UI: Use after free enables local privilege escalation
Summary
A use-after-free vulnerability in the Windows Credential User Interface allows an authorized local attacker to elevate privileges. The attacker needs an existing low-privileged account or foothold on the system, and high attack complexity applies. No user interaction is required, and the CVSS base score is 7.0 (High).
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
- Install the November 2026 cumulative update for each affected Windows version (builds at or above the fixed versions listed under affected).
- KB numbers: Unknown.
Workaround
Unknown.
Exploitation
- No exploitation in the wild known at the time of research (CISA SSVC: Exploitation none, Automatable no, Technical Impact total).
- No public proof-of-concept exploit found.
- Not listed in CISA KEV in the sources checked.
Our recommendation
- Inventory Windows 10 and Windows Server hosts by build number and identify affected systems.
- Apply the November 2026 cumulative update, prioritizing shared workstations, terminal servers and systems where untrusted users run.
- Verify the final affected list and KB mapping on the MSRC advisory, as secondary sources were not fully confirmed.
- Check support status of older builds such as 1607 and 1809, as they may no longer receive updates.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Credential User Interface
- 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 Response Center: CVE-2026-96978 msrc.microsoft.com
- CVE Record CVE-2026-96978 (CVE.org) www.cve.org
- Offseq: CVE-2026-96978 (Windows 10 1607) radar.offseq.com
- Strix.ai: CVE-2026-96978 www.strix.ai
- Rapid7: Patch Tuesday November 2026 www.rapid7.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, 07:31.
Original description (NVD)
Use after free in Windows Credential User Interface 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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