CVE-2026-43219

The bug in the Linux kernel’s cpsw_new driver allows an erroneous call to unregister a network device that has never been registered. If an error occurs during the registration of the first MAC address, the driver may later attempt to unregister the second MAC, which could then reference a null or uninitialized interface and trigger a kernel panic. This flaw represents a logic or validation error rather than an information disclosure or remote code execution flaw; an attacker would need to cause the register_netdev failure locally to exploit it.

All Linux kernel builds that include the cpsw_new driver – the issue was fixed by the commit that added a check for the device’s registration state before calling unregister_netdev. No specific version range is listed, so any kernel revision prior to the patch is potentially vulnerable.

The CVSS score of 5.5 indicates a moderate severity. The EPSS score of <1% indicates a very low probability of exploitation. The flaw necessitates a local or privileged context to trigger the error during network device registration. If exploited, it causes a kernel crash, resulting in a loss of availability. The vulnerability is not listed in the CISA KEV catalog, implying no known public exploits at the time of analysis.