Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2026-69789
Published: October 13, 2026
Vulnerability identifier: #VU154422
CSH Severity: Medium
CVSS v4: 7.7 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-69789
CWE-ID: CWE-122
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to heap-based buffer overflow in Reliable Multicast Transport Driver (RMCAST) when handling communication over an adjacent network. A remote attacker can exploit the vulnerable driver over an adjacent network to execute arbitrary code.
Successful exploitation requires a specific target system configuration and knowledge of that configuration.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-69789
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7725, 10 22H2 10.0.19045.7725, 10 1607 10.0.14393.9512, 10 1809 10.0.17763.9245, 11 23H2 10.0.22631.7582, 11 24H2 10.0.26100.9445, 11 25H2 10.0.26200.9445, 11 26H1 10.0.28000.2954
Windows Server - addressed in versions 2012 R2 6.3.9600.23398, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622, 2025 10.0.26100.33438
Windows Server - addressed in versions 2012 R2 6.3.9600.23398, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622, 2025 10.0.26100.33438