CVE-2026-64588: Linux

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix data races on ring->ready On weakly-ordered architectures, the store to fiq->ops can be reordered past the store to ring->ready, allowing a CPU that sees ring->ready == true via fuse_uring_ready() to dispatch requests through a stale fiq->ops pointer. Upgrade the store to smp_store_release() and the load in fuse_uring_ready() to smp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...) is visible to any CPU that observes ring->ready == true. Additionally, fuse_uring_do_register() publishes ring->ready with WRITE_ONCE() but the fast-path check reads it with a plain load. This is a marked-vs-unmarked access that KCSAN will flag. Wrap it in READ_ONCE() to mark it without adding unnecessary ordering. Also wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to prevent the compiler from reloading it between the NULL check and the dereference.

Affected products

• Linux Linux: from 6.14, before 6.18.39 (fixed in 6.18.39); from 6.19, before 7.1.4 (fixed in 7.1.4)

Published 2026-08-06. Last modified 2026-08-17.