CVE-2026-64209 in Linux
Summary
by MITRE • 07/24/2026
In the Linux kernel, the following vulnerability has been resolved:
phy: qcom: qmp-usbc: Fix out-of-bounds array access in dp swing config
swing_tbl and pre_emphasis_tbl are 4x4 arrays (valid indices 0-3), but the boundary check uses "> 4" instead of ">= 4", allowing index 4 to cause an out-of-bounds access.
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Analysis
by VulDB Data Team • 07/24/2026
The vulnerability identified in the Linux kernel's qcom qmp-usbc phy driver represents a critical out-of-bounds array access flaw that could potentially lead to system instability or arbitrary code execution. This issue resides within the usb type-c physical layer implementation responsible for managing display port swing configurations in Qualcomm-based systems. The affected component specifically handles the dp swing configuration table and pre_emphasis table arrays, both of which are designed as 4x4 structures with valid index ranges from 0 through 3.
The technical flaw manifests in an incorrect boundary validation mechanism that employs a greater-than comparison against 4 instead of a greater-than-or-equal-to check. This seemingly minor logical error creates a critical vulnerability where array indexing operations can access memory locations beyond the allocated array boundaries. When the driver processes certain configuration parameters, it can legitimately attempt to use index 4, which falls outside the valid range of 0-3 for both swing_tbl and pre_emphasis_tbl arrays. The improper boundary check fails to prevent this invalid access, resulting in unauthorized memory reads or writes that could corrupt kernel data structures.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially enabling privilege escalation attacks that could allow malicious actors to gain elevated system privileges. According to the common weakness enumeration framework, this flaw maps directly to cwe-129, which describes improper validation of array indices and other forms of out-of-bounds memory access. The attack surface is particularly concerning given that this vulnerability exists within a kernel driver that operates with high privileges and interfaces directly with hardware components. Systems utilizing Qualcomm qcom qmp-usbc phy controllers are at risk when processing specific usb type-c configuration data, especially in scenarios involving display port connectivity.
Mitigation strategies should prioritize immediate patch application from upstream kernel maintainers, as the fix involves correcting the boundary check logic to properly validate array indices against the actual valid range. System administrators should also implement runtime monitoring for suspicious memory access patterns and consider disabling unnecessary usb type-c functionality when not actively required. The attack technique aligns with tactics described in the mitre attack framework under initial access and privilege escalation categories, particularly focusing on kernel-level exploitation methods that leverage memory corruption vulnerabilities to achieve system compromise. Organizations should conduct thorough vulnerability assessments of their embedded systems and mobile devices that utilize Qualcomm hardware components to identify potential exposure to this specific flaw.