CVE-2026-90407

A flaw was found in the Linux kernel's ath11k Wi-Fi driver. This vulnerability arises from insufficient validation of firmware input, specifically the num_vdevs field, which is used as a loop bound without proper size checks. An attacker could exploit this to trigger an out-of-bounds read, potentially leading to information disclosure from kernel memory. This issue occurs during the processing of Channel Switch Announcement (CSA) events.

A moderate-impact out-of-bounds read was found in the Linux kernel ath11k Wi-Fi driver as shipped in Red Hat Enterprise Linux 8, 9 and 10 (kernel and kernel-rt), Red Hat In-Vehicle OS, and OpenShift Container Platform (RHEL CoreOS). When the driver processes a Channel Switch Announcement (CSA) switch count status event, no WMI TLV policy entry enforces a minimum length for the event structure, and the firmware-supplied num_vdevs value is used as a loop bound over the vdev_ids array without checking that it fits within the TLV payload. Either condition lets the driver read past the end of the event buffer, which can result in disclosure of kernel memory contents or a kernel panic and system crash. Red Hat scores this flaw 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), lower than the upstream CVEORG score of 7.7 (IMPORTANT, CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H), because the malformed data that triggers the overread originates from the Wi-Fi firmware on the local system rather than input an attacker directly injects, and Red Hat assessed the practical impact as availability loss (kernel panic) rather than meaningful information disclosure. Red Hat Enterprise Linux 6 and 7 are not affected because the vulnerable code is not present. Fixes for the affected streams are currently deferred to a future update; the residual risk until then is an out-of-bounds read triggered by a malformed firmware CSA event, limited to systems using affected ath11k Wi-Fi hardware.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.