A race exists between futex_key_to_node_opt() and vma_replace_policy() in the Linux kernel. During concurrent mbind() calls the old mempolicy is freed while futex_key_to_node_opt() still reads it. This leads to a use‑after‑free read of the mpol->mode field, potentially causing a kernel crash or leaking kernel memory content. The bug manifests as a KASAN slab-use-after-free error in __futex_key_to_node, as shown in the stack trace from the kernel trace logs.

All Linux kernel builds that contain the unpatched futex routine are affected. The vulnerability applies to every distribution that ships a kernel version before the commit that adds RCU protection to __mpol_put(). Vendor product names such as "Linux:Linux" denote the operating system itself; no specific product name is required because the kernel is common across distributions.

The CVSS score of 5.5 classifies the flaw as moderate severity. An EPSS score below 1 % and the absence of a listing in CISA's KEV catalog indicate a low overall exploitation probability. Exploitation requires a local or privileged attacker to orchestrate a race between futex usage and mbind() operations, which is non‑trivial. Consequently, while the impact is significant on a compromised system, the likelihood of real‑world exploitation remains low under normal operating conditions.