CVE-2026-23103 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux kernel versions 4.17 to 6.19-rc6. They should review and apply the provided patches to ensure the addrs_lock is properly used per-port. They should also update Linux kernel to a version that includes the fix and monitor for potential issues with ipvlan address management.

Technical summary

The Linux kernel's ipvlan implementation had a race condition vulnerability due to the addrs_lock being shared among all ipvlan devices instead of being per-port. This was fixed by introducing per-port addrs_lock and updating relevant code to use the new lock. The vulnerability had a CVSS score of 7.8 and was considered HIGH severity. The issue has been resolved by making the addrs_lock per-port. The fix involves introducing per-port addrs_lock and updating relevant code.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the provided patches to ensure the addrs_lock is properly used per-port
• Update Linux kernel to a version that includes the fix
• Monitor for potential issues with ipvlan address management
• 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 2026-02-04T17:16:21.177Z and last modified on 2026-07-14T13:18:24.807Z. The NVD entry is currently Modified. The Linux kernel's ipvlan implementation had a race condition vulnerability due to the addrs_lock being shared among all ipvlan devices instead of being per-port. This was fixed by introducing per-port addrs_lock and updating relevant code to use the new lock. The vulnerability had a CVSS score of 7.8 and was considered HIGH severity. The issue has been resolved by making the addrs_lock per-port. Evidence limits suggest that this issue could potentially cause false negatives in ipvlan_addr_busy() and races when adding or removing addresses.

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.