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CVE Record

CVE-2025-38663: nilfs2: reject invalid file types when reading inodes

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject invalid file types when reading inodes To prevent inodes with invalid file types from tripping through the vfs and causing malfunctions or assertion failures, add a missing sanity check when reading an inode from a block device. If the file type is not valid, treat it as a filesystem error.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-38663 is a Linux kernel NILFS2 filesystem bug. A malformed or corrupt NILFS2 inode with an invalid file type could pass into normal kernel filesystem handling and cause malfunctions or assertion failures. The public data does not provide CVSS, confirmed exploitation, or a complete distro-by-distro impact statement.

Executive priority

Treat this as a targeted kernel hardening issue unless NILFS2 is used or untrusted filesystem images are handled. Prioritize normal kernel patch cycles, with faster action for systems that mount external or user-supplied block devices.

Technical view

The kernel fix adds a missing inode sanity check in NILFS2. When reading an inode from a block device, the kernel now rejects invalid file types and treats them as filesystem errors instead of allowing them into VFS processing.

Likely exposure

Exposure is most likely on Linux systems that run affected kernel builds and mount or process NILFS2 filesystems, disk images, removable media, or block devices. Systems that do not enable or use NILFS2 are less likely to be exposed, based on the provided sources.

Exploitation context

The sources describe a malformed filesystem condition leading to kernel malfunctions or assertion failures. They do not state active exploitation, remote exploitability, privilege escalation, or public weaponization. KEV status is false in the supplied bundle.

Researcher notes

Evidence is limited to the CVE record, Linux stable commits, and Debian LTS announcements. The vulnerability is in NILFS2 inode validation before VFS handling. No CVSS, CWE, exploit status, or detailed impact beyond malfunction/assertion failure is provided.

Mitigation direction

  • Update Linux kernels using vendor or stable-kernel guidance for CVE-2025-38663.
  • Apply relevant Debian LTS kernel updates if using affected Debian LTS releases.
  • Avoid mounting untrusted NILFS2 filesystems or disk images until patched.
  • Confirm whether NILFS2 support is enabled or used in your Linux fleet.

Validation and detection

  • Inventory Linux kernel versions across affected servers, endpoints, and appliances.
  • Check vendor advisories for fixed packages matching CVE-2025-38663.
  • Verify the relevant kernel stable commit or downstream backport is present.
  • After patching, confirm systems booted into the updated kernel.
  • Review whether NILFS2 mounts are present in operational environments.
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

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CVE-2025-38663 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
1ADP providers
11Source links

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184, 05fe58fdc10df9ebea04c0eaed57adc47af5c184unaffected
LinuxLinux2.6.30, 0, 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9, 6.16affected
Weakness

CWE details

No CWE listed

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