CVE-2026-90303: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set, a user fault may trigger show_pte() without any lock. If another thread in the same process concurrently calls munmap(), the page table pages may be freed while show_pte() is still traversing them, causing a use-after-free in show_pte(). If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table of PMD are freed when show_pte() is running. Acquire mmap_write_lock() around show_pte() for user faults to fix the contention. For user faults, additionally restrict that show_pte() is called only when the addr is a user-space address (addr < TASK_SIZE). This is because the lock of tsk->mm only protects the virtual memory of user address space, furthermore, dumping the page tables of a kernel-space address for user faults is unnecessary and may have security implications. Keep everything unchanged for kernel faults, because the kernel is already in the "oops" state, acquiring a lock may risk a deadlock.

Affected products

• Linux Linux: from 4.0, before 5.10.270 (fixed in 5.10.270); from 5.11, before 5.15.221 (fixed in 5.15.221); from 5.16, before 6.1.188 (fixed in 6.1.188); from 6.2, before 6.6.157 (fixed in 6.6.157); from 6.7, before 6.12.110 (fixed in 6.12.110); from 6.13, before 6.18.52 (fixed in 6.18.52); …

Published 2026-09-17. Last modified 2026-09-17.