CVE-2025-38247: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: userns and mnt_idmap leak in open_tree_attr(2) Once want_mount_setattr() has returned a positive, it does require finish_mount_kattr() to release ->mnt_userns. Failing do_mount_setattr() does not change that. As the result, we can end up leaking userns and possibly mnt_idmap as well.

Affected products

• Linux Linux Kernel: from 6.15, before 6.15.5 (fixed in 6.15.5); version 6.16 only

Published 2025-07-09. Last modified 2026-06-17.