LiveActive security incident?Get immediate response
CVE Record

CVE-2025-38058: __legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock

In the Linux kernel, the following vulnerability has been resolved: __legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock ... or we risk stealing final mntput from sync umount - raising mnt_count after umount(2) has verified that victim is not busy, but before it has set MNT_SYNC_UMOUNT; in that case __legitimize_mnt() doesn't see that it's safe to quietly undo mnt_count increment and leaves dropping the reference to caller, where it'll be a full-blown mntput(). Check under mount_lock is needed; leaving the current one done before taking that makes no sense - it's nowhere near common enough to bother with.

HighCVSS 7.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A timing flaw in Linux mount cleanup can mishandle a final mount reference when unmount operations overlap. An attacker needs local, low-privileged access, so this is not a direct internet attack. Successful exploitation could seriously affect confidentiality, integrity, and availability according to the supplied CVSS assessment, although the sources do not document a demonstrated outcome.

Executive priority

Treat this as accelerated kernel maintenance, particularly across multi-user and shared-compute estates. Its local-access requirement places it below an unauthenticated remote emergency, but the high impact rating supports prompt patching and reboot coordination. Do not infer active attacks from severity alone.

Technical view

The MNT_SYNC_UMOUNT check in __legitimize_mnt() occurred outside mount_lock, creating a race between increasing mnt_count and a synchronous unmount setting the flag. The caller could consequently perform a full mntput() instead of quietly reversing the increment. Stable-kernel commits move the check under the lock.

Likely exposure

Exposure is limited to systems running affected Linux kernels where an attacker already has local low-privileged execution. Shared servers and platforms running untrusted workloads merit particular attention. The supplied version data spans multiple kernel lines through 6.15 but is not expressed as reliable package ranges; map exact distribution builds against vendor advisories and stable fixes.

Exploitation context

The supplied CVSS is 7.8: local access, low complexity, low privileges, and no user interaction, with potentially high impact. CVE-2025-38058 is not identified as KEV, and the provided sources contain no evidence of active exploitation, public weaponization, or proven exploit reliability.

Researcher notes

This is a mount-reference synchronization defect whose essential correction is lock placement. The sources establish the race and branch-specific fixes but do not establish a specific exploitation primitive, observed crash signature, privilege-escalation path, or affected distribution package boundary. Validation should therefore rely primarily on kernel build provenance and vendor mappings.

Mitigation direction

  • Apply the distribution or appliance vendor's kernel update incorporating the relevant stable fix.
  • Reboot into the updated kernel; installing a package alone may leave the vulnerable kernel active.
  • Prioritize shared Linux hosts and systems executing untrusted or tenant-controlled local workloads.
  • Consult vendor guidance for affected package versions and any supported interim risk-reduction measures.

Validation and detection

  • Inventory running kernel versions and distinguish them from merely installed kernel packages.
  • Map each distribution kernel build to its vendor advisory or applicable Linux stable fix.
  • Confirm systems booted into the updated kernel after maintenance.
  • Review local-access and workload exposure while remediation remains pending.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2025-38058 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
2ADP providers
12Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2025-38058Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455, 48a066e72d970a3e225a9c18690d570c736fc455unaffected
LinuxLinux3.13, 0, 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.