CVE-2025-39763: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered If a synchronous error is detected as a result of user-space process triggering a 2-bit uncorrected error, the CPU will take a synchronous error exception such as Synchronous External Abort (SEA) on Arm64. The kernel will queue a memory_failure() work which poisons the related page, unmaps the page, and then sends a SIGBUS to the process, so that a system wide panic can be avoided. However, no memory_failure() work will be queued when abnormal synchronous errors occur. These errors can include situations like invalid PA, unexpected severity, no memory failure config support, invalid GUID section, etc. In such a case, the user-space process will trigger SEA again. This loop can potentially exceed the platform firmware threshold or even trigger a kernel hard lockup, leading to a system reboot. Fix it by performing a force kill if no memory_failure() work is queued for synchronous errors. [ rjw: Changelog edits ]

Affected products

• Linux Linux Kernel: before 6.6.103 (fixed in 6.6.103); from 6.7, before 6.12.43 (fixed in 6.12.43); from 6.13, before 6.15.11 (fixed in 6.15.11); from 6.16, before 6.16.2 (fixed in 6.16.2)

Published 2025-09-11. Last modified 2026-06-17.