CVE-2026-31738

A flaw was found in the Linux kernel's Virtual Extensible LAN (VXLAN) implementation. A remote attacker could exploit this vulnerability by sending specially crafted Neighbor Discovery (ND) options to the vxlan_na_create function. This could cause the parser to read beyond the intended memory boundaries or use an incorrectly sized source Link-Layer Address (LLADDR) option payload, potentially leading to memory corruption and system instability or a denial of service.

VXLAN neighbor-advertisement construction must bound ND option lengths before parsing. Red Hat recommends patched kernels on VXLAN deployments; unload vxlan where overlays are unused.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the vxlan module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.