CVE-2026-83877 in Windows
Summary
by MITRE • 10/14/2026
Integer overflow or wraparound in HID Parser Library allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified involves a critical integer overflow condition within the Human Interface Device (HID) parser library, which serves as a foundational component for interpreting input data from peripheral devices such as keyboards, mice, and game controllers. This specific flaw arises when the parsing logic fails to adequately validate or constrain numerical values during the processing of HID report descriptors. In many operating systems, particularly those utilizing Windows-based architectures where this library is prevalent, these parsers are executed with high privileges because they interact directly with kernel-mode drivers responsible for managing hardware interrupts and input streams. When an attacker crafts a maliciously constructed HID descriptor that triggers an integer overflow or wraparound during size calculation or buffer allocation, the resulting arithmetic error can lead to incorrect memory management decisions by the underlying system components.
From a technical perspective, this flaw typically manifests when a value intended to represent a small quantity wraps around due to exceeding the maximum limit of its data type, often converting a large positive number into a negative one or a very small positive integer depending on signedness assumptions. This miscalculation can cause the system to allocate insufficient memory for subsequent operations or write beyond the bounds of allocated buffers. Because the HID parser operates at a low level within the operating system stack, exploiting this condition allows an attacker to corrupt kernel memory structures. The corruption may overwrite critical pointers or control flow data, effectively bypassing standard security boundaries that separate user-mode applications from privileged kernel-space resources.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation. An authorized attacker who has already gained access to the system can leverage this flaw to execute arbitrary code with SYSTEM-level privileges. This transformation from a standard user account to an administrator or root-equivalent status grants the adversary complete control over the affected machine. With such elevated rights, the attacker can install persistent backdoors, disable security software, exfiltrate sensitive data without detection, and pivot to other systems within the network infrastructure. The ability to escalate privileges locally is particularly dangerous as it often serves as a prerequisite for more advanced attack vectors in multi-user environments or cloud instances where initial access might be limited but lateral movement requires higher credentials.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-190, which defines integer overflow or wraparound errors that can lead to subsequent security weaknesses such as buffer overflows or logic flaws. Furthermore, in the context of the MITRE ATT&CK framework, this exploit technique corresponds to T1068 Exploitation for Privilege Escalation, specifically highlighting how software vulnerabilities are leveraged to gain higher-level access on a compromised host. The attack vector is classified as Local (T1059), requiring physical or logical interaction with the target system prior to exploitation.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Organizations should prioritize applying vendor-provided security patches that address the input validation logic within the HID parser library, ensuring that all numerical inputs are strictly bounded before being used in memory allocation or arithmetic operations. Developers reviewing similar codebases should implement rigorous bounds checking and utilize safe integer libraries that prevent wraparound behavior by detecting potential overflows prior to execution. Additionally, enabling kernel-level protections such as Kernel Address Space Layout Randomization (KASLR) and Data Execution Prevention (DEP) can mitigate the impact of memory corruption exploits by making it significantly more difficult for attackers to reliably predict target addresses or execute injected code. Regular auditing of input parsing routines against CWE-190 guidelines is essential to prevent recurrence in future software updates.