CVE-2025-68764

Local mount restriction bypass via flag loss

Published Jan 5, 2026 · Updated Jan 5, 2026

Improper mount-option inheritance in the Linux Kernel allows local users to bypass restrictions on NFS automounts. The nfs_d_automount function creates a submount filesystem context without copying the parent flags covered by NFS_SB_MASK, losing ro, noexec, nodev, or sync policy. Access to an NFS referral or crossed filesystem boundary is required; the resulting submount permits operations that the parent mount policy forbids.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper mount-option inheritance in the Linux Kernel allows local users to bypass restrictions on NFS automounts. The nfs_d_automount function creates a submount filesystem context without copying the parent flags covered by NFS_SB_MASK, losing ro, noexec, nodev, or sync policy. Access to an NFS referral or crossed filesystem boundary is required; the resulting submount permits operations that the parent mount policy forbids.

The record

CVE
CVE-2025-68764
Published
Jan 5, 2026
Updated
Jan 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=5.6
  2. Affected versionversion=f2aedb713c284429987dc66c7aaf38decfc8da2a <4b296944e632cf4c6a4cc8e2585c6451eae47b1b
  3. Affected versionversion=f2aedb713c284429987dc66c7aaf38decfc8da2a <612cc98698d667df804792f0c47d4e501e66da29
  4. Affected versionversion=f2aedb713c284429987dc66c7aaf38decfc8da2a <8675c69816e4276b979ff475ee5fac4688f80125
  5. Affected versionversion=f2aedb713c284429987dc66c7aaf38decfc8da2a <df9b003a2ecacc7218486fbb31fe008c93097d5f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.6; version=f2aedb713c284429987dc66c7aaf38decfc8da2a <4b296944e632cf4c6a4cc8e2585c6451eae47b1b; version=f2aedb713c284429987dc66c7aaf38decfc8da2a <612cc98698d667df804792f0c47d4e501e66da29; version=f2aedb713c284429987dc66c7aaf38decfc8da2a <8675c69816e4276b979ff475ee5fac4688f80125; version=f2aedb713c284429987dc66c7aaf38decfc8da2a <df9b003a2ecacc7218486fbb31fe008c93097d5f

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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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

T1068Exploitation for Privilege Escalation

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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