A flaw was found in the Linux kernel's wifi implementation wherein an attacker within wireless range is able to abuse a logic flaw in the wifi implementation by reassembling packets from multiple fragments under different keys and they would be treated as valid. This allows an attacker to send a fragment under an incorrect key and be treated as a valid fragment under the new key.

Upstream patch: https://lore.kernel.org/linux-wireless/20210511200110.3f8290e59823.I622a67769ed39257327a362cfc09c812320eb979@changeid/