The vulnerability arises from a buffer length underflow (CWE-124) in the Linux kernel’s mt76 mt7921 wireless driver. The buf_len value limits iterations for retrieving the country power setting, and under specific conditions the length may underflow when the power table in CLC changes. This brings the driver into an almost infinite loop or an invalid power setting, leading to driver initialization failure and preventing the wireless interface from functioning.

This issue affects Linux systems running any kernel that includes the mt76 mt7921 driver prior to the fix. The specific kernel versions that contain the vulnerability are not listed in the available data, but the problem exists in all releases where the mt7921 driver is compiled with the CLC power table code without the applied patch.

The CVSS score of 5.5 indicates moderate severity for this defect—a buffer underflow leading to an infinite loop or invalid power setting. The EPSS score is < 1 %, suggesting a very low but non-zero likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector is a malicious or erroneous wireless transmission or configuration change that initiates the mt7921 driver, potentially from an attacker in proximity to the device or through a compromised power table configuration. If the flaw is triggered, the driver may hang or fail to boot its network stack, resulting in a denial of service at the system or interface level.