CVE-2025-38247

userns and mnt_idmap leak in open_tree_attr(2)

MEDIUM
5.5
CVSS Score
Published: July 9, 2025 at 10:42 AM UTC
Updated: June 17, 2026 at 09:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.15 ≤ v < 6.15.56.15 ≤ v < 6.166.156.16 rc16.16 rc26.16 rc3c4a16820d90199409c9bf01c4f794e1e9e8d8fd8
Vendor states this is fixed in 0748e553df0225754c316a92af3a77fdc057b358 (fixed)
Vendor states this is fixed in 142db4e76110dd80239f4e79810f85ea1735ad60 (fixed)
Vendor states this is fixed in 6.15 (unaffected)
Vendor states this is fixed in 6.15.5 (unaffected)
Vendor states this is fixed in 6.16 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0748e553df0225754c316a92af3a77fdc057b358
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/142db4e76110dd80239f4e79810f85ea1735ad60

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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