CVE-2025-38247 | userns and mnt_idmap leak in open_tree_attr(2)

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.

Published: 2025-07-09 Last update: 2025-11-19 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-38247 is rated Low Risk (29.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38247

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 0.02% 0.07% +0.06%
2 2025-07-09 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38247

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-38247

OS Trackers for CVE-2025-38247

vendor priority summary link
debian unimportant CVE-2025-38247 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-38247
redhat medium — https://access.redhat.com/security/cve/CVE-2025-38247
suse medium CVE-2025-38247 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 281 product×package rows across 55 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (55 product lines)): Known Not Affected 281. https://www.suse.com/security/cve/CVE-2025-38247/
ubuntu medium CVE-2025-38247 medium priority: Ubuntu including 144 source packages (linux, linux-allwinner-5.19, …), 1286 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): DNE 922, ignored 151, not-affected 136, released 77. https://ubuntu.com/security/CVE-2025-38247

Affected software / configurations for CVE-2025-38247

Vendor Product Version Raw CPE
linux linux_kernel >= 6.15, < 6.15.5 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*

References for CVE-2025-38247

cvelogic Threat Intelligence