CVE-2025-39716: Debian Linux

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: parisc: Revise __get_user() to probe user read access Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel executes at privilege level 0, so __get_user() never triggers a read access interruption (code 26). Thus, it is currently possible for user code to access a read protected address via a system call. Fix this by probing read access rights at privilege level 3 (PRIV_USER) and setting __gu_err to -EFAULT (-14) if access isn't allowed. Note the cmpiclr instruction does a 32-bit compare because COND macro doesn't work inside asm.

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: from 2.6.13, before 6.1.149 (fixed in 6.1.149); from 6.2, before 6.6.103 (fixed in 6.6.103); from 6.7, before 6.12.44 (fixed in 6.12.44); from 6.13, before 6.16.4 (fixed in 6.16.4); version 2.6.12 only

Published 2025-09-05. Last modified 2026-06-17.