CVE-2026-83795 in Windows
Summary
by MITRE • 10/14/2026
Heap-based buffer overflow in Windows IKE Extension allows an unauthorized attacker to deny service over a network.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified involves a heap-based buffer overflow within the Internet Key Exchange (IKE) extension component of Microsoft Windows operating systems. This specific flaw arises from improper memory management practices during the processing of crafted or malformed network packets destined for the IKE service. When an attacker sends specially constructed data to the vulnerable system, the application fails to adequately validate the length and boundaries of the input before writing it to a pre-allocated heap buffer. Consequently, excess data overwrites adjacent memory locations on the heap, corrupting internal data structures that manage dynamic memory allocation. This type of error is fundamentally categorized under CWE-122, which denotes a heap-based buffer overflow, representing a critical failure in boundary checks during runtime operations involving dynamically allocated memory regions.
The operational impact of this vulnerability centers primarily on service denial rather than arbitrary code execution or privilege escalation, although the potential for exploitation varies based on specific system configurations and patch levels. By triggering the heap corruption through network-delivered malicious payloads, an unauthorized attacker can cause the IKE extension process to crash or become unresponsive. Since Internet Key Exchange is a core component of IPsec implementations used for establishing secure channels in virtual private networks (VPNs) and other authenticated communications, disrupting this service effectively breaks connectivity for systems relying on it. This results in a denial-of-service condition where legitimate users are unable to establish encrypted tunnels or maintain existing secure sessions, leading to significant operational disruptions in environments dependent on IPsec-based security policies.
From an offensive perspective, the exploitation of this vulnerability aligns with techniques observed in the MITRE ATT&CK framework, specifically under resource hijacking and denial-of-service categories such as T1498 Network Denial of Service or potentially T1053 Scheduled Task/Job if persistence mechanisms were involved in a broader attack chain. The attacker leverages network-level access to send malicious traffic that exploits the memory handling flaw without requiring authentication, making it an attractive target for remote exploitation by threat actors seeking to disrupt infrastructure availability. The lack of proper input validation allows the exploit to be triggered remotely over standard IPsec ports, facilitating wide-scale impact across vulnerable networks where IKE services are exposed or actively used for site-to-site connections.
Mitigation strategies must focus on applying vendor-supplied security updates that address the underlying memory management errors within the Windows IKE extension. Organizations should prioritize patching all affected systems to ensure that boundary checks and length validations are correctly implemented during packet processing. In addition to software remediation, network segmentation and firewall rules can be employed to restrict access to IPsec services from untrusted networks, thereby reducing the attack surface available to potential adversaries. Monitoring for anomalous traffic patterns indicative of buffer overflow attempts, such as unusually large or malformed IKE packets, can also provide early detection capabilities while patching efforts are underway. Continuous vulnerability management and adherence to secure coding standards that emphasize rigorous input validation are essential preventive measures against similar heap-based vulnerabilities in network services.