CVE-2026-68166

Local code execution via shadow-stack page injection

Published Aug 10, 2026 · Updated Aug 10, 2026

Code injection in Linux allows local users with userfaultfd access to execute arbitrary code via shadow-stack page replacement. vma_can_userfault() accepts a VM_SHADOW_STACK VMA, letting UFFDIO_COPY replace a discarded shadow-stack page with attacker-chosen return addresses. The path requires local userfaultfd access; successful replacement defeats return-address protection and redirects control flow in the affected process.

CVSS severity7.3
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Linux allows local users with userfaultfd access to execute arbitrary code via shadow-stack page replacement. vma_can_userfault() accepts a VM_SHADOW_STACK VMA, letting UFFDIO_COPY replace a discarded shadow-stack page with attacker-chosen return addresses. The path requires local userfaultfd access; successful replacement defeats return-address protection and redirects control flow in the affected process.

The record

CVE
CVE-2026-68166
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-94
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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=54007f818206dc27309ca423df4c87dd160a7208 <0c26202b157f1efc3cd2f26f5c30f59b508a6a5d
  2. Affected versionversion=54007f818206dc27309ca423df4c87dd160a7208 <165613191ad9d034bf17c00e3a142f9561597ec5
  3. Affected versionversion=54007f818206dc27309ca423df4c87dd160a7208 <3c58f641e813c3c71039f8fd4d4e2a3aab713288
  4. Affected versionversion=6.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=54007f818206dc27309ca423df4c87dd160a7208 <0c26202b157f1efc3cd2f26f5c30f59b508a6a5d; version=54007f818206dc27309ca423df4c87dd160a7208 <165613191ad9d034bf17c00e3a142f9561597ec5; version=54007f818206dc27309ca423df4c87dd160a7208 <3c58f641e813c3c71039f8fd4d4e2a3aab713288; version=6.6

Published CVSS scores

7.3Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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