CVE-2026-20465 in MT6890
Summary
by MITRE • 08/03/2026
In wlan AP driver, there is a possible out of bounds write due to a missing bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00489200; Issue ID: MSV-7834.
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability resides within the wireless local area network access point driver component, specifically manifesting as an out-of-bounds write condition that stems from insufficient input validation mechanisms. The flaw occurs when the driver fails to properly verify array boundaries during processing of incoming wireless frames or configuration parameters, creating a scenario where maliciously crafted data can overwrite adjacent memory locations beyond the intended buffer allocation. Such missing bounds checks represent a fundamental security weakness that directly aligns with CWE-129, which categorizes improper validation of array indices as a critical software defect leading to potential memory corruption vulnerabilities.
The exploitation of this vulnerability enables remote privilege escalation attacks targeting systems running affected wireless access point firmware, where adversaries positioned within proximity to the targeted network can leverage this flaw without requiring any additional privileges or user interaction. This makes the vulnerability particularly dangerous in enterprise environments where wireless infrastructure serves as a critical communication backbone. The attack vector operates through adjacent network positioning, allowing threat actors to inject malicious payloads that trigger the out-of-bounds write condition when the driver processes crafted wireless frames, potentially leading to complete system compromise and unauthorized administrative access.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to execute arbitrary code within the kernel space of the affected device, potentially allowing for persistent backdoor establishment, network traffic interception, or lateral movement within the compromised wireless domain. From an adversarial perspective, this vulnerability maps directly to ATT&CK technique T1068, which covers locally executed commands and T1547.001 for registry run keys persistence, since the elevated privileges gained through exploitation can be leveraged to establish long-term access points within the wireless infrastructure. The lack of user interaction requirements significantly increases exploitability and reduces the attack surface complexity.
Mitigation strategies should prioritize immediate firmware updates from the vendor, specifically addressing patch WCNCR00489200 which resolves the bounds checking deficiency in the wlan AP driver component. Network administrators should implement additional monitoring controls to detect anomalous wireless traffic patterns that might indicate exploitation attempts, while also considering network segmentation approaches to limit potential lateral movement if compromise occurs. The vulnerability demonstrates the critical importance of input validation in kernel-level drivers and highlights how seemingly minor coding oversights can create significant security implications. Security teams should conduct comprehensive assessments of wireless infrastructure components to identify similar vulnerabilities and implement robust memory safety practices, including bounds checking mechanisms, to prevent analogous issues from emerging in future deployments.