CVE-2026-23436 Linux CVE debrief

Who should care

Users of Linux kernel versions 6.13.1 to 6.18.20, 6.19 to 6.19.10, and specific release candidates of version 7.0 should apply patches to mitigate this vulnerability. Linux kernel users and administrators should review and apply patches as recommended by the Linux kernel maintainers.

Technical summary

The Linux kernel's shaper component had a vulnerability that could lead to hierarchy leaks due to a race condition. This was resolved by taking the instance lock in pre-callbacks, preventing the netdev from being unregistered between ref taking and locking. Patches have been applied to affected versions, specifically for Linux kernel versions 6.13.1 to 6.18.20, 6.19 to 6.19.10. The vulnerability has a CVSS score of 5.5 and a severity of MEDIUM. Users of these versions should review and apply patches as recommended by the Linux kernel maintainers to mitigate this vulnerability. Evidence is limited to public sources and may not reflect the full scope or impact of the vulnerability. Defenders should verify affected systems and apply patches or mitigations as recommended.

Defensive priority

Medium priority due to CVSS score of 5.5 and availability impact.

Recommended defensive actions

• Apply patches provided by the Linux kernel maintainers.
• Inventory and update affected Linux kernel versions.
• Monitor for potential exploitation attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-04-03T16:16:25.257Z and last modified on 2026-07-24T21:10:00.143Z. The NVD entry is currently Analyzed. Evidence is limited to public sources and may not reflect the full scope or impact of the vulnerability. Defenders should verify affected systems and apply patches or mitigations as recommended by the Linux kernel maintainers.

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.