CVE-2026-15417 in silabser.sys driver
Summary
by MITRE • 09/10/2026
In the silabser.sys Windows 8 driver for CP210x devices, a local unprivileged user can use incorrect driver settings to cause a kernel crash.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/10/2026
The vulnerability identified in the silabser.sys driver, which serves as the interface between Windows operating systems and Silicon Labs CP210x USB-to-serial converter devices, represents a critical flaw in how the kernel-mode component handles input parameters from user-space applications. This specific issue allows any local unprivileged user to trigger a system crash by exploiting incorrect or malformed driver settings during device communication. The root cause lies within the driver's failure to adequately validate and sanitize inputs before processing them at the kernel level, leading to an unstable state that results in a stop error or blue screen of death. This type of flaw is characteristic of improper input validation mechanisms where the software assumes that data received from user-mode applications is always well-formed and safe for immediate execution within the privileged context of the operating system core.
From a technical perspective, this vulnerability falls under the category of CWE-20: Improper Input Validation, as the driver does not perform sufficient checks on the parameters passed to it via IOCTL requests or other communication channels. The lack of boundary checking and type verification allows malicious actors to craft specific sequences that exceed expected limits or contain invalid structures, causing memory corruption or logic errors within the kernel space. Because silabser.sys operates with high privileges as part of the Windows driver model, any instability caused by such inputs directly impacts system stability rather than just crashing a single user application. This aligns closely with MITRE ATT&CK technique T1059: Command and Scripting Interpreter, where attackers might leverage local privilege escalation paths or denial-of-service vectors to disrupt service availability before attempting further exploitation steps.
The operational impact of this vulnerability is primarily centered around system reliability and availability rather than direct data exfiltration or remote code execution in its current form. A successful exploit results in a kernel panic, forcing the affected machine to reboot unexpectedly. For environments relying on serial communication for industrial control systems, legacy hardware integration, or embedded device management, such unexpected reboots can lead to significant downtime and potential loss of unsaved data or interrupted processes. While the immediate effect is denial of service, the presence of a kernel-level crash bug often indicates deeper architectural weaknesses that could potentially be chained with other vulnerabilities for privilege escalation if additional conditions are met. Attackers targeting high-security environments might use this DoS vector as part of a broader attack strategy to mask more intrusive activities or to disrupt critical infrastructure operations dependent on stable serial connectivity.
Mitigation strategies should focus on both immediate patching and long-term architectural improvements. The most effective remediation is the installation of vendor-provided updates that address these input validation flaws within silabser.sys, ensuring that all IOCTL requests are rigorously checked against expected bounds and data types before being processed by the kernel driver. Administrators should also consider restricting physical access to systems running vulnerable versions of this driver if possible, as the exploit requires local unprivileged user access. Additionally, implementing strict device control policies through Windows Group Policy or endpoint detection and response solutions can limit which users are allowed to interact with USB-to-serial devices, thereby reducing the attack surface. Regular auditing of installed drivers and keeping them updated according to manufacturer advisories remains essential for maintaining system integrity against such kernel-level vulnerabilities.