CVE-2026-54982 in Windows
Summary
by MITRE • 07/14/2026
Integer underflow (wrap or wraparound) in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.
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Analysis
by VulDB Data Team • 07/14/2026
The vulnerability described represents a critical integer underflow condition within the Reliable Multicast Transport Driver component of network communication systems, specifically affecting the rmcast module. This flaw manifests when the driver processes multicast packets and fails to properly validate integer values during packet processing operations, creating a scenario where arithmetic operations can wrap around to negative values. The underlying technical mechanism involves the driver's handling of sequence numbers or packet counters that are expected to remain within positive integer ranges but can be manipulated by an attacker to cause unexpected behavior in the system's memory management and control flow.
The operational impact of this vulnerability is severe as it enables remote code execution within the adjacent network segment, requiring only network access to exploit. An unauthorized attacker positioned within the same broadcast domain can craft malicious multicast packets that trigger the integer underflow condition, potentially leading to buffer overflows, memory corruption, or arbitrary code execution within the vulnerable system. This type of vulnerability is classified as a CWE-191 Integer Underflow (Wrap or Wraparound) which falls under the broader category of integer arithmetic errors that frequently lead to exploitable conditions in network drivers and kernel modules. The attack vector operates through standard network protocols without requiring authentication, making it particularly dangerous for systems running multicast transport services.
The security implications extend beyond simple code execution as this vulnerability can be leveraged for privilege escalation and persistent access within the compromised network segment. Attackers can exploit the wraparound condition to manipulate memory layouts, overwrite critical data structures, or redirect program execution flow through return-oriented programming techniques. The adjacent network requirement means that physical proximity or network compromise is sufficient to initiate attacks, making this vulnerability particularly concerning for enterprise environments where multicast traffic is common and network segmentation may be insufficient. This aligns with ATT&CK technique T1059.007 Command and Scripting Interpreter: Python, as attackers can leverage the compromised system to establish persistent access points.
Mitigation strategies must address both immediate patching requirements and broader network security measures. System administrators should prioritize applying vendor-specific patches that correct the integer validation logic within the rmcast driver module, ensuring proper bounds checking and overflow protection mechanisms are implemented. Network segmentation approaches including firewall rules and multicast traffic filtering can limit the attack surface by restricting unauthorized access to multicast services. Additionally, implementing network monitoring solutions capable of detecting anomalous multicast packet patterns and implementing intrusion detection systems can provide early warning capabilities. The vulnerability demonstrates the critical importance of proper integer validation in kernel space drivers as outlined in industry best practices for secure coding standards and represents a prime example of why robust input validation and boundary checking are essential defensive measures against memory corruption exploits.