Windows: Use-after-free in Bind Filter Driver allows local privilege escalation
Summary
A use-after-free vulnerability in the Windows Bind Filter Driver (bindflt.sys) allows a local attacker with low privileges to elevate privileges, potentially to SYSTEM level. The attack requires local access and a high-complexity condition. The vulnerability is not directly reachable from the internet, but it is relevant on shared hosts, terminal servers and workstations where Sandbox, containers or development tools are used.
Affected
- Windows 11 version 23H2: 10.0.22631.0 to before 10.0.22631.7652
- Windows 11 version 24H2: 10.0.26100.0 to before 10.0.26100.9711
- Windows 11 version 25H2: 10.0.26200.0 to before 10.0.26200.9711
- Windows 11 version 26H1: 10.0.28000.0 to before 10.0.28000.3231
- Windows 11 version 26H2: 10.0.26300.0 to before 10.0.26300.9711
- Windows Server 2025 (including Server Core): 10.0.26100.0 to before 10.0.26100.33650
Fixed in
- Windows 11 23H2: 10.0.22631.7652 or later
- Windows 11 24H2: 10.0.26100.9711 or later
- Windows 11 25H2: 10.0.26200.9711 or later
- Windows 11 26H1: 10.0.28000.3231 or later
- Windows 11 26H2: 10.0.26300.9711 or later
- Windows Server 2025: 10.0.26100.33650 or later
KB numbers: Unknown (not verified; check the MSRC Security Update Guide).
Workaround
- Unknown. No official workaround from Microsoft is known; applying the update is the fix.
- Disabling the Bind Filter Driver is an unofficial suggestion only. It may break Store apps, Windows Sandbox and containers, so use it only as a last resort after testing.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, not automatable, technical impact total.
- EPSS below 1%.
- No public proof of concept found.
- Known exploitation in the wild: none found.
Our recommendation
- Apply the October 2026 cumulative update (or the later build listed above) in the next regular monthly patch cycle.
- Prioritise terminal servers, shared hosts and workstations with Sandbox, containers or development tools.
- Include Windows Server 2025 in the inventory, not only Windows 11 23H2.
- Check for signs of compromise on shared systems if there is any suspicion of a local foothold.
- Recheck the NVD record and the MSRC advisory before rollout.
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 Update Guide (MSRC) msrc.microsoft.com
- OpenCVE CVE-2026-83900 app.opencve.io
- Vulners NVD:CVE-2026-83900 vulners.com
- Strix CVE-2026-83900 www.strix.ai
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 4 Nov 2026, 08:01.
Original description (NVD)
Use after free in Windows Bind Filter Driver 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.