Integer Overflow or Wraparound Affecting kernel6.18-tools-devel package, versions <1:6.18.39-79.141.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.15% (6th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL618TOOLSDEVEL-18907808
  • published18 Aug 2026
  • disclosed25 Jul 2026

Introduced: 25 Jul 2026

NewCVE-2026-64267  (opens in a new tab)
CWE-190  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.18-tools-devel to version 1:6.18.39-79.141.amzn2023 or higher.
This issue was patched in ALAS2023-2026-2045.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.18-tools-devel package and not the kernel6.18-tools-devel 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:

fuse: avoid 32-bit prune notification count wrap

FUSE_NOTIFY_PRUNE validates the nodeid payload length with:

size - sizeof(outarg) != outarg.count * sizeof(u64)

On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path.

Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.

CVSS Base Scores

version 3.1