CVE-2026-90890 Overview
CVE-2026-90890 is an untrusted pointer dereference vulnerability [CWE-822] in the ASRock Polychrome SYNC/RGB software utility developed by ASRock Inc. The driver bundled with the utility fails to validate pointer values supplied through I/O control (IOCTL) requests. Authenticated local attackers can send a specially crafted IOCTL to force the driver to dereference an unvalidated pointer, causing an operating system crash. The flaw affects availability but does not expose confidentiality or integrity. It was published to the National Vulnerability Database (NVD) on 2026-09-14 and last modified on 2026-09-18.
Critical Impact
A local user with low privileges can trigger a kernel-mode crash resulting in denial of service on affected Windows hosts running the ASRock Polychrome driver.
Affected Products
- ASRock Polychrome SYNC software utility
- ASRock Polychrome RGB software utility
- Windows systems where the vulnerable ASRock Polychrome driver is installed
Discovery Timeline
- 2026-09-14 - CVE-2026-90890 published to NVD
- 2026-09-18 - Last updated in NVD database
Technical Details for CVE-2026-90890
Vulnerability Analysis
The vulnerability resides in the kernel-mode driver installed by the ASRock Polychrome SYNC/RGB utility. The driver exposes an IOCTL interface that user-mode components use to control RGB lighting features. One or more IOCTL handlers accept pointer values from user-mode input without validating that the pointers reference legitimate, accessible kernel structures. When the driver dereferences the attacker-controlled pointer, the resulting invalid memory access triggers a bugcheck and forces the operating system into a crash state.
The issue is classified under [CWE-822] Untrusted Pointer Dereference. This weakness class arises when a program obtains a pointer from an untrusted source and uses it without sanity checks such as ProbeForRead or ProbeForWrite in Windows kernel code. The vulnerability requires local access and authenticated low-privileged access on the target host.
Root Cause
The driver trusts pointer arguments contained in the IOCTL input buffer. It performs the dereference operation directly instead of validating pointer alignment, address range, and access rights against the caller's context. This design allows any process capable of opening a handle to the driver's device object to pass arbitrary pointer values into privileged code.
Attack Vector
An authenticated local attacker opens a handle to the vulnerable driver's device object using CreateFile and issues a crafted DeviceIoControl request. The IOCTL input buffer contains a malformed or non-canonical pointer value. When the driver dereferences the value in kernel context, the processor raises an access violation that the kernel converts into a bugcheck, terminating the operating system.
No verified proof-of-concept exploit code has been published. The vulnerability mechanism is described in the TWCA Security Advisory.
Detection Methods for CVE-2026-90890
Indicators of Compromise
- Unexpected Windows bugchecks (BSOD) on systems with the ASRock Polychrome driver installed, particularly with stop codes referencing invalid memory access in the vendor driver module.
- Minidumps identifying the ASRock Polychrome driver as the faulting module in the crash stack trace.
- Presence of the vulnerable driver loaded on endpoints that do not require RGB lighting management.
Detection Strategies
- Inventory endpoints for the ASRock Polychrome SYNC/RGB driver and cross-reference against the vulnerable versions listed in the vendor advisory.
- Monitor Windows Event Log for BugCheck (Event ID 1001) entries citing the ASRock driver as the failing component.
- Hunt for non-administrative processes opening handles to the ASRock driver device object and issuing DeviceIoControl calls.
Monitoring Recommendations
- Enable kernel crash dump collection so responders can attribute repeated crashes to a specific driver and IOCTL code.
- Alert on unexpected loads of vendor driver files outside of normal software installation windows.
- Track process telemetry for low-privileged users interacting with hardware utility drivers not required for their role.
How to Mitigate CVE-2026-90890
Immediate Actions Required
- Identify all hosts with the ASRock Polychrome SYNC/RGB utility installed and prioritize remediation on shared or multi-user systems.
- Apply the vendor-supplied update referenced in the TWCA Security Advisory as soon as it becomes available.
- Restrict interactive local access on systems where the vulnerable driver cannot be removed immediately.
Patch Information
Refer to the TWCA Security Advisory and the TWCA Security Notification published by the Taiwan Computer Emergency Response Team for the vendor-provided fixed version and update instructions.
Workarounds
- Uninstall the ASRock Polychrome SYNC/RGB utility on endpoints where RGB lighting control is not a functional requirement.
- Unload or disable the vulnerable driver service so it cannot be opened by user-mode callers.
- Enforce least privilege on local accounts to reduce the population of users who can authenticate and issue IOCTL requests.
# Query and stop the ASRock Polychrome driver service (run elevated)
sc query type= driver | findstr /I "AsrDrv Polychrome"
sc stop <DriverServiceName>
sc config <DriverServiceName> start= disabled
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
