Time-of-check Time-of-use (TOCTOU) Affecting kernel6.18-tools package, versions <1:6.18.41-94.142.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.12% (3rd percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL618TOOLS-19811999
  • published15 Sept 2026
  • disclosed28 Aug 2026

Introduced: 28 Aug 2026

NewCVE-2026-80675  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.18-tools to version 1:6.18.41-94.142.amzn2023 or higher.
This issue was patched in ALAS2023-2026-2071.

NVD Description

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

libbpf: Reject non-exclusive metadata maps in the signed loader

The loader verifies map->sha against the metadata hash in its instructions. map->sha is calculated when BPF_OBJ_GET_INFO_BY_FD is called on the frozen map.

While the map is frozen, the /signed loader/ must also ensure the map is exclusive, as, without exclusivity (which a hostile host could just omit when loading the loader), another BPF program with map access can mutate the contents afterwards, so the check passes on stale data.

With the extra check as part of the signed loader, it now refuses to move on with map->sha validation if the host set it up wrongly.

CVSS Base Scores

version 3.1