Out-of-Range MCS Vulnerability in ath11k Wireless Driver by Linux Kernel

CVE-2026-93271

What is CVE-2026-93271?

The ath11k wireless driver in the Linux kernel was found to handle incoming HT/VHT/HE frames with an invalid MCS (Modulation and Coding Scheme) value incorrectly. Specifically, when the reported MCS exceeded the limit for the associated mac80211 rate space, the driver failed to properly assign rate status. This incorrectly flagged otherwise valid frames, leading to loss of data due to frame rejection by the rate sanity check. This defect has been addressed to ensure that valid frames are not dropped and that the reported MCS is capped to the communicative constraints of the established protocol, thereby enhancing the overall reliability of wireless communications.

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