CVE-2026-90232 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux systems that utilize the amt feature should review and apply the patch to prevent potential issues with amt cross-netns setup.

Why it matters

A vulnerability in the Linux kernel's amt feature has been addressed. Defenders should review and apply the patch to prevent potential issues with amt cross-netns setup. Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux systems that utilize the amt feature should take action to verify and apply the patch.

• Defenders should verify Linux kernel versions and apply patches to prevent potential issues with amt cross-netns setup.
• Linux kernel developers and maintainers should review and apply the patch to prevent potential issues with amt cross-netns setup.
• Users of Linux systems that utilize the amt feature should monitor for any potential issues related to amt and cross-netns setup.

Technical summary

The Linux kernel's amt feature did not properly support cross-netns setup, which could lead to issues when a lower device is unregistered. This has been resolved by forbidding cross-netns setup. The affected versions are prior to the commits a457ff1189f22c2f15f69df55dc910b8b6d7a77d, 5ebaad6cf2a639afbf0b265f9a7d1fb6f656a37e, 569eb11f0990849ba48706a2bfa743273707e254, e1dc0af719a2566ae7ccb82c0a11f70aa54908e9, and e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the patch to the Linux kernel to prevent potential issues with amt cross-netns setup.
• Verify that the Linux kernel version is not affected by checking the version numbers provided in the source item.
• Monitor for any potential issues related to amt and cross-netns setup in the Linux kernel.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and source item provide details about the vulnerability and its resolution in the Linux kernel. The NVD entry is currently not provided. The vulnerability was addressed by forbidding cross-netns setup. The affected versions are prior to the commits a457ff118f22c2f15f69df55dc910b8b6d7a77d, 5ebaad6cf2a639afbf0b265f9a7d1fb6f656a37e, 569eb11f0990849ba48706a2bfa743273707e254, e1dc0af719a2566ae7ccb82c0a11f70aa54908e9, and e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06. Defenders should verify Linux kernel versions and apply patches

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.