CVE-2026-64522: Linux

High severity, CVSS 8.8. EPSS: 0.5% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix eswitch mode block underflow on IPsec acquire SA mlx5e_xfrm_add_state() handles acquire-flow temporary SAs by allocating software state and skipping hardware offload setup. That path jumps to the common success label before taking the eswitch mode block. After tunnel-mode validation was moved earlier, the common success label unconditionally calls mlx5_eswitch_unblock_mode(). For acquire SAs, this decrements esw->offloads.num_block_mode without a matching increment. Return directly after installing the acquire SA offload handle, so only the paths that successfully called mlx5_eswitch_block_mode() call the matching unblock.

Affected products

• Linux Linux: from 6.17.4, before 6.18 (fixed in 6.18); from 6.18, before 6.18.34 (fixed in 6.18.34); from 6.19, before 7.0.11 (fixed in 7.0.11)

Published 2026-07-25. Last modified 2026-07-27.