CVE-2025-68266

Kernel crash via unvalidated BFS inode types

Published Dec 16, 2025 · Updated Dec 16, 2025

Improper input validation in Linux BFS allows local users to crash the kernel by mounting a filesystem with corrupted inode metadata. The inode loader in fs/bfs/inode.c trusts file-type bits from the on-disk mode and attributes fields instead of masking the unused mode bits and accepting only BFS_VREG or BFS_VDIR. Exploitation requires local access sufficient to present and mount a crafted BFS image, and the documented consequence is loss of host availability.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in Linux BFS allows local users to crash the kernel by mounting a filesystem with corrupted inode metadata. The inode loader in fs/bfs/inode.c trusts file-type bits from the on-disk mode and attributes fields instead of masking the unused mode bits and accepting only BFS_VREG or BFS_VDIR. Exploitation requires local access sufficient to present and mount a crafted BFS image, and the documented consequence is loss of host availability.

The record

CVE
CVE-2025-68266
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <34ab4c75588c07cca12884f2bf6b0347c7a13872
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <77899444d46162aeb65f229590c26ba266864223
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a8cb796e7e2cb7971311ba236922f5e7e1be77e6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <34ab4c75588c07cca12884f2bf6b0347c7a13872; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <77899444d46162aeb65f229590c26ba266864223; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a8cb796e7e2cb7971311ba236922f5e7e1be77e6

Published CVSS scores

5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo