Use After Free Vulnerability in Microsoft Windows Reliable Multicast Transport Driver
CVE-2026-78449

8.1HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1607
Windows 10 Version 1809
Windows 10 Version 21h2
Windows 10 Version 22h2
Vendor
CVE Published:
8 September 2026

What is CVE-2026-78449?

A use after free vulnerability in the Reliable Multicast Transport Driver (RMCAST) in Microsoft Windows could allow attackers to execute arbitrary code remotely by sending specially crafted packets over the network. This type of vulnerability exploits improperly managed memory in the driver, which could lead to severe security consequences if left unaddressed.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.9512

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.9245

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.7725

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.