CVE-2026-74626

The ntb_netdev driver in the Linux kernel forwards received packets to the network stack before allocating a replacement socket buffer. If the allocation fails, the packet is lost and the driver does not repost a buffer. Every such failure removes one buffer from the receive queue, and repeated failures gradually drain the queue until the NIC can no longer accept traffic, effectively stopping the interface and causing a denial‑of‑service attack. The weakness is a resource management flaw, identified as CWE‑826.

All Linux kernel installations that load the ntb_netdev module for near‑field interface bridges are potentially affected. The problem exists in any kernel version prior to the recent patch and therefore applies to servers routers, storage controllers, or virtual hosts configured with the NTB interface. The scope covers any system where the ntb_netdev driver has been loaded, not just the kernel itself, because the failure condition is specific to the driver implementation.

The CVSS score of 7.5 classifies the issue as high severity. The EPSS score of less than 1% indicates that the vulnerability is currently considered unlikely to be exploited, and it is not listed in the CISA KEV catalog. However, because the flaw is triggered by repeated allocation failures, an attacker could potentially bring it out of a low‑probability state by generating sustained traffic or applying memory pressure to a vulnerable system, thereby draining the receive queue and disabling the interface. The lack of an official workaround means the risk remains until a kernel update is applied.