CVE-2025-40362

Cross-filesystem write access via mismatched filesystem names

Published Dec 16, 2025 · Updated Dec 16, 2025

Authorization bypass in the Linux kernel CephFS client allows remote authenticated users to write or delete files beyond granted access. The MDS authorization-capability match accepts a capability associated with another filesystem because it fails to compare the mounted filesystem name. A user needs valid Ceph credentials for multiple filesystems with different grants; the stronger grant then permits unauthorized creation or deletion on the restricted filesystem.

CVSS severityUnavailable
Unscored
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in the Linux kernel CephFS client allows remote authenticated users to write or delete files beyond granted access. The MDS authorization-capability match accepts a capability associated with another filesystem because it fails to compare the mounted filesystem name. A user needs valid Ceph credentials for multiple filesystems with different grants; the stronger grant then permits unauthorized creation or deletion on the restricted filesystem.

The record

CVE
CVE-2025-40362
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1485
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 <07640d34a781bb2e39020a39137073c03c4aa932
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <22c73d52a6d05c5a2053385c0d6cd9984732799d
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <07640d34a781bb2e39020a39137073c03c4aa932; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <22c73d52a6d05c5a2053385c0d6cd9984732799d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523

Published CVSS scores

No CVSS assessment is available in this record.

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

T1485Data Destruction

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

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Your stack

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