CVE-2026-53180: linux Improper Locking

Vulnerability summary

CVE-2026-53180 is a high (CVSS 7.5) Improper Locking vulnerability in linux. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26% of scored vulnerabilities.

Timeline

1. 25-06-2026
   PublishedVulnerability first disclosed.
2. 19-10-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: timers/migration: Fix livelock in tmigr_handle_remote_up() tmigr_handle_remote_cpu() skips timer_expire_remote() when cpu == smp_processor_id(), assuming the local softirq path already handled this CPU's timers. This assumption is wrong because jiffies can advance after the handling of the CPU's global timers in run_timer_base(BASE_GLOBAL) and before tmigr_handle_remote() evaluates the expiry times. As a consequence a timer which expires after the CPU local timer wheel advanced and becomes expired in the remote handling is ignored and the callback is never invoked and removed from the timer wheel. What's worse is that fetch_next_timer_interrupt_remote() keeps reporting it as expired, and the event is re-queued with expires == now on each iteration. The goto-again loop spins indefinitely. Fix this by calling timer_expire_remote() unconditionally. That's minimal overhead for the common case as __run_timer_base() returns immediately if there is nothing to expire in the local wheel. [ tglx: Amend change log and add a comment ]

• CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
• CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.