The RDMA/rxe driver in the Linux kernel contains a flaw that allows an attacker to send a single UDP packet with an undefined opcode (such as 0xff) to a port used by the driver. The driver incorrectly validates packet length for unknown opcodes, leading to an integer underflow during checksum calculation. This underflow causes an out‑of‑bounds read of the packet payload, which in turn triggers a kernel panic. The result is a denial of service and, in a worst‑case scenario, could enable an attacker to manipulate kernel memory if the overflow were exploitable beyond the observed crash.

The vulnerability is present in any Linux kernel that includes the RDMA/rxe module. No specific kernel release is listed, but the issue is known to exist in the 7.0-rc7 release when the module is loaded and a RDMA link is created. All systems running a kernel with the RDMA/rxe driver and without the recent packet validation fix are affected.

While the CVSS score is not provided, the impact of a kernel panic represents a high‑severity condition. The exploitation path requires only the ability to send a crafted UDP packet to the target system; no authentication or additional configuration is needed. EPSS information is not available, and the vulnerability is not yet listed in the CISA KEV catalog, but the zero‑auth nature of the trigger and the potential for service disruption make it a significant risk.