CVE-2026-83898 in Windows
Summary
by MITRE • 10/14/2026
Out-of-bounds read in HID Parser Library allows an authorized attacker to disclose information locally.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified within the Human Interface Device (HID) Parser Library represents a critical memory safety flaw classified as an out-of-bounds read, which corresponds directly to Common Weakness Enumeration identifier CWE-125. This specific type of error occurs when software attempts to access data at a memory location that is outside the boundaries of the intended buffer or array structure. In the context of HID parsing, this typically involves processing input reports from peripheral devices such as keyboards, mice, game controllers, or specialized industrial interfaces. The parser is responsible for interpreting raw binary data streams into structured events that an operating system can understand and act upon. When a malformed or maliciously crafted report exceeds expected dimensions without proper validation checks, the parsing logic may read memory addresses adjacent to the allocated buffer space rather than stopping at the valid boundary.
From a technical perspective, this flaw arises due to insufficient bounds checking during the traversal of HID usage tables or descriptor structures. The parser likely relies on indices derived from the input data itself to determine how much information to process. If an attacker controls these indices through a connected device that sends oversized or malformed descriptors, they can manipulate the pointer arithmetic used by the library. Instead of triggering an immediate crash due to segmentation faults in some implementations, out-of-bounds reads often result in silent memory disclosure. The application continues execution but inadvertently exposes sensitive contents of adjacent heap or stack memory regions back to the user space process that initiated the parsing operation. This behavior is particularly dangerous because it does not always cause a denial of service, allowing the attack to remain stealthy while achieving its primary objective of information leakage.
The operational impact of this vulnerability centers on local privilege escalation and sensitive data exfiltration by an authorized attacker. Since HID devices are typically connected via USB or Bluetooth interfaces that require physical access or user interaction for pairing, the threat actor must have some level of initial access to the system. However, once authenticated as a legitimate peripheral, the ability to trigger this out-of-bounds read allows the extraction of arbitrary memory contents. This can include cryptographic keys stored in process memory, session tokens, passwords cached by applications, or internal state information that reveals details about other running processes. The disclosure is local in nature, meaning it does not require network exposure, but it significantly compromises the confidentiality guarantees provided by the operating system's isolation mechanisms. Attackers leveraging this flaw can map out the memory layout of target processes to facilitate further exploitation techniques such as return-oriented programming or heap spraying attacks.
This vulnerability aligns with several tactics within the MITRE ATT&CK framework, specifically relating to Collection and Credential Access via peripheral devices. The attack vector involves abusing trusted hardware interfaces to bypass standard security controls that might otherwise protect against remote code execution or network-based intrusions. By exploiting a parser library rather than an application directly, the attacker targets a foundational component of input handling, increasing the likelihood of successful exploitation across multiple software products that rely on the same underlying HID parsing infrastructure. The persistence and impact are limited to the local session unless combined with other vulnerabilities for privilege escalation, but the initial foothold gained through memory disclosure can be highly valuable in complex attack chains targeting enterprise environments where physical security is assumed or compromised.
Mitigation strategies must focus on rigorous input validation and defensive programming practices within the HID Parser Library itself. Developers should implement strict bounds checking before any array access or pointer dereference operation, ensuring that all indices derived from external data are validated against known maximum limits defined by the USB HID specification. Utilizing static analysis tools configured to detect buffer over-reads during the development phase is essential for identifying these logic errors early in the software lifecycle. Additionally, employing memory-safe programming languages or libraries with built-in safety guarantees can prevent such vulnerabilities from manifesting at runtime. For system administrators and end-users, limiting physical access to USB ports through hardware locks or disabling unused HID interfaces reduces the attack surface available to potential attackers. Keeping all firmware and driver updates current ensures that vendor-provided patches addressing these parsing flaws are applied promptly, closing the gap between vulnerability discovery and operational exposure.