CVE-2026-23040
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211_hwsim: fix typo in frequency notification The NAN notification is for 5745 MHz which corresponds to channel 149 and not 5475 which is not actually a valid channel. This could result in a NULL pointer dereference in cfg80211_next_nan_dw_notif.
Statement
The mac80211_hwsim virtual WiFi driver contains an incorrect frequency constant used when generating NAN discovery window notifications on the 5 GHz band that can lead to Null pointer deref. In mac80211_hwsim_nan_dw_start the driver calls ieee80211_get_channel with 5475 MHz when nan_curr_dw_band is NL80211_BAND_5GHZ. That frequency does not correspond to a valid channel in typical wiphy channel tables so ieee80211_get_channel may return NULL. Subsequent NAN notification processing in cfg80211 may then dereference the channel pointer and crash the kernel in cfg80211_next_nan_dw_notif leading to a denial of service. The issue is most relevant in test and simulation environments where mac80211_hwsim is loaded and NAN simulation is enabled. A local attacker with permissions to configure wireless interfaces and NAN behavior can trigger the faulty path by enabling NAN simulation and causing 5 GHz NAN discovery window scheduling.
Mitigation
To mitigate this issue, prevent module mac80211_hwsim from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.6 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | Low | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
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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