CVE-2026-43110
Description
A flaw was found in the Linux kernel's brcmfmac Wi-Fi driver. This vulnerability occurs because the driver fails to properly validate bsscfg indices in interface (IF) events. An attacker could exploit this by sending a specially crafted IF event with an invalid bsscfg index, which could lead to an out-of-bounds write or read, potentially causing a system crash and resulting in a denial of service (DoS).
Statement
brcmfmac IF event handling validates the firmware provided ifidx but still uses the raw bsscfgidx value as an index into the driver iflist array. A malformed firmware IF event with an out of range bsscfgidx can cause an out of bounds pointer read and may lead to an invalid pointer dereference or broader memory corruption depending on how the resulting ifp is used. For the CVSS the PR:N is used in the paranoid score because a practical attacker model may involve adjacent Wi-Fi influence over FullMAC firmware events rather than a local privileged user on the host. The issue is not reachable over a normal routed IP network. It is adjacent network or device firmware mediated. Impact is at least denial of service through a kernel crash or Wi-Fi driver failure. In the paranoid case, the unchecked firmware controlled array index potentially could lead to possible confidentiality and integrity impact (but primarily only Availability impact).
Mitigation
To mitigate this issue, prevent module brcmfmac 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 | 7.5 | N/A | 8.8 |
| Attack Vector | Adjacent Network | N/A | Adjacent Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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