Arbitrary Code Injection Affecting kernel6.18-headers package, versions <1:6.18.44-99.149.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-AMZN2023-KERNEL618HEADERS-19813083
  • published15 Sept 2026
  • disclosed10 Aug 2026

Introduced: 10 Aug 2026

CVE-2026-68166  (opens in a new tab)
CWE-94  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.18-headers to version 1:6.18.44-99.149.amzn2023 or higher.
This issue was patched in ALAS2023-2026-2106.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.18-headers package and not the kernel6.18-headers package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

userfaultfd: prevent registration of special VMAs

Vova Tokarev says:

userfaultfd allows registration on shadow stack VMAs. With userfaultfd access, you can register on the shadow stack, discard a page ... and inject a page with chosen return addresses via UFFDIO_COPY.

Update vma_can_userfault() to reject VM_SHADOW_STACK.

While on it, also reject VM_SPECIAL so that if a driver would implement vm_uffd_ops, it wouldn't be possible to register special VMAs with userfaultfd.

Since VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude hugetlb VMAs from the check for VM_SPECIAL.

CVSS Base Scores

version 3.1