CVE-2026-90393 Affecting kernel-tools-devel package, versions <1:6.1.188-233.385.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.23% (13th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELTOOLSDEVEL-20871624
  • published13 Oct 2026
  • disclosed17 Sept 2026

Introduced: 17 Sep 2026

NewCVE-2026-90393  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-tools-devel to version 1:6.1.188-233.385.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3197.

NVD Description

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

bpf: Fix potential UAF in bpf_netns_link_update_prog

In bpf_netns_link_update_prog, the checks for old_prog and prog type are currently performed locklessly before acquiring netns_bpf_mutex. This creates a race condition that can lead to a UAF issue.

If two threads concurrently execute BPF_LINK_UPDATE on the same netns link, the following execution path can trigger a UAF:

CPU0 CPU1 bpf_netns_link_update_prog if (old_prog && old_prog != link->prog) return -EPERM; bpf_netns_link_update_prog if (old_prog && old_prog != link->prog) ... old_prog = xchg(&link->prog, new_prog); bpf_prog_put(old_prog); if (new_prog->type != link->prog->type) <-- trigger UAF

Fix this by moving the old_prog and prog->type checks inside the netns_bpf_mutex critical section. Meanwhile, use guard() to simplify lock management and avoid all the goto jumping.