CVE-2026-23396
Description
A flaw was found in the Linux kernel's mac80211 component. An adjacent attacker can exploit this by sending a specially crafted Channel Switch Announcement (CSA) action frame. This frame, containing a valid Mesh ID Information Element (IE) but lacking a Mesh Configuration IE, can trigger a NULL pointer dereference within the kernel. Successful exploitation leads to a system crash, resulting in a Denial of Service (DoS).
Statement
This vulnerability requires the attacker to be on the same wireless mesh network as the target system, limiting exploitation to adjacent network scenarios. Systems not configured for 802.11s mesh networking are not affected. The impact is limited to denial of service through a kernel crash, with no data exposure or code execution.
Mitigation
To mitigate this issue, prevent the mac80211 module from being loaded. See https://access.redhat.com/solutions/41278 for instructions. Note that this will disable WiFi functionality entirely.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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