CVE-2026-69530: Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability
Published Sep 8, 2026
·Updated
Use after free in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over a network.
Other sources
Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability
— Microsoft
Affected Software
14 affected componentsFixes available
Microsoft Windows RMCAST (Reliable Multicast Transport Driver)
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
Microsoft Windows Server 2022<10.0.20348.5622
Microsoft Windows Server 2025<10.0.26100.33438
Remediation
Event History
Sep 8, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·05:19 PM
Data Sourced
via MITRE·05:19 PM
DescriptionSeverity
Data Sourced
via NVD·06:19 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
Which systems are listed as affected?
The affected software list includes Microsoft Windows Server 2025, Windows Server 2022, Windows Server 2019, Windows 10, and Microsoft Windows RMCAST (Reliable Multicast Transport Driver).
2
Does an attacker need credentials or user interaction to exploit this issue?
No privileges and no user interaction are indicated by the CVSS vector. The attack vector is network-based, although the attack complexity is rated high.