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


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.66% (49th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL618TOOLSDEVEL-19468961
  • published1 Sept 2026
  • disclosed15 Aug 2026

Introduced: 15 Aug 2026

NewCVE-2026-72451  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.18-tools-devel 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-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:

xfrm: Fix xfrm state cache insertion race

The xfrm input state cache insertion code checks the validity of the state before acquiring the global xfrm_state_lock. Thus it's possible for someone else to kill the state after it passed the validity check, and then the insertion will add the dead state to the cache.

Fix this by moving the validity check inside the lock.

This entire function is called on the input path, where BH must be off (e.g., the caller of this function xfrm_input acquires its spinlocks without disabling BH).

So there is no need to disable BH here or take the RCU read lock. Remove both and replace them with an assertion that trips if BH is accidentally enabled on some future calling path.

CVSS Base Scores

version 3.1