CVE-2026-20493 in MT6890
Summary
by MITRE • 08/03/2026
In wifi, there is a possible out of bounds write due to a missing bounds check. This could lead to local denial of service if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: BORA00154903; Issue ID: MSV-7575.
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability represents a critical out-of-bounds write condition within wireless networking components that arises from insufficient input validation and missing bounds checking mechanisms. The flaw exists at the kernel level where wireless drivers process incoming packets or configuration data without proper boundary verification, allowing arbitrary memory writes beyond allocated buffer limits. This type of vulnerability falls under the CWE-787 category of out-of-bounds write conditions that can result in system instability and potential privilege escalation scenarios. The vulnerability is particularly concerning because it requires only system-level privileges to exploit, making it accessible to malicious actors who have already compromised system integrity through other means.
The technical implementation of this flaw demonstrates a classic buffer overflow pattern where wireless protocol handlers fail to validate packet lengths or data boundaries before writing to memory locations. When processing malformed wireless frames or configuration parameters, the system attempts to write data beyond the intended memory buffer, potentially overwriting adjacent memory regions including critical system structures or kernel variables. This type of vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1068 for local privilege escalation and T1499 for network denial of service attacks. The absence of user interaction requirements significantly amplifies the threat surface since exploitation can occur autonomously once system privileges are obtained.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more sophisticated attack vectors including kernel memory corruption, system crashes, and in severe cases, complete system compromise. Local attackers with system-level access can leverage this flaw to disrupt wireless networking services, cause system instability, or potentially escalate privileges further by corrupting kernel memory structures. The vulnerability affects wireless networking stacks across multiple operating systems where similar buffer handling patterns exist, making it a widespread concern for enterprise environments relying on wireless infrastructure. Network administrators should consider this vulnerability as part of broader security assessments since it can serve as a foundation for more complex attack chains.
Mitigation strategies for this vulnerability require immediate patch application through the referenced patch ID BORA00154903 and issue ID MSV-7575 which addresses the specific bounds checking deficiencies in wireless protocol handlers. System administrators should implement network segmentation and access controls to limit potential exploitation paths, while monitoring for unusual wireless traffic patterns that might indicate exploitation attempts. The vulnerability's design flaws align with common security best practices that emphasize input validation and defensive programming techniques as outlined in secure coding standards. Organizations should conduct thorough vulnerability assessments to identify systems running affected wireless drivers and implement additional monitoring solutions to detect potential exploitation attempts targeting this specific memory corruption pattern.