The vulnerability lies in the Linux kernel's handling of out‑of‑band (OOB) sockets for AF_UNIX streams. When a process performs a recv() with MSG_PEEK after an OOB packet has been sent, the kernel incorrectly skips the OOB buffer and returns NULL instead of updating its last‑seen marker. This causes the read routine to enter a busy‑wait loop that continuously consumes CPU without progressing. An attacker can trigger this behavior by creating a local socket pair and sending one or more OOB packets as described, causing the system to cycle through the busy‑wait state and saturate the processor. The direct outcome is a denial of service manifested as extreme CPU usage, which can degrade or halt other legitimate workloads.

Linux kernel implementations are affected, as the advisory lists Linux:Linux as the CNA vendor/product. No specific kernel version list is supplied, so any kernel that has not yet incorporated the commit that updates the last skb marker may be vulnerable. This includes a broad range of distributions that ship the standard upstream kernel.

The CVSS score of 5.5 and an EPSS score of < 1% indicate a moderate severity with a low likelihood of exploitation. The bug still requires only local code execution to trigger the CPU‑hungry busy‑wait; an attacker with local access can quickly force the system into a DoS state. The vendor has not listed the advisory in the CISA KEV catalog, but the impact is enough to disrupt critical services. The fix is a kernel patch that correctly updates the last skb marker; until that change is applied, the vulnerability remains exploitable locally.