The Linux kernel networking driver attempts to perform PHY‑driven SFP cage probing while using genphy drivers, which runs under the RTNL lock. This path was never intended for genphy, leading to a deadlock on the RTNL lock and halting the kernel’s network stack. The deadlock prevents the kernel from progressing with synchronization primitives, causing the system to become unresponsive and resulting in a denial of service. The weakness is a concurrency error that permits a local attacker to trigger a kernel deadlock.

All Linux kernels that include the genphy code path for PHY drivers are vulnerable. The flaw appears in any distribution that ships a kernel built before the patch commit 5a0082ec20a05ef2378410323a5089a8f1786f4a. The vendor is Linux, though no specific version range is listed in the advisory; any kernel compiled without the fix is impacted.

The vulnerability has no publicly available exploit, and its EPSS score is not released. Nevertheless, a successful exploitation requires local access or control over network interfaces to load or reconfigure drivers, making it a high‑impact kernel deadlock. The lack of KEV listing suggests limited exploitation exposure, but the severity of the denial of service remains significant.