CVE-2026-46170 Linux CVE debrief

Who should care

Linux kernel maintainers, users, and administrators should be aware of this vulnerability and take steps to mitigate it. The affected operator is the Linux kernel maintainer, and the platform is the Linux kernel. The vulnerability-management impact is high, and the security-team impact is medium. The recommended actions are to review and apply patches for the Linux kernel and to monitor Linux kernel updates for potential vulnerabilities.

Why it matters

A use-after-free vulnerability in the Linux kernel's MPTCP implementation requires local access and specific configuration to exploit, but patches are available to mitigate the vulnerability.

• Denial-of-service condition due to use-after-free error
• Potential for local privilege escalation
• Requires local access and specific configuration to exploit
• Patches are available to mitigate the vulnerability

Technical summary

The vulnerability is caused by a use-after-free error in the MPTCP implementation of the Linux kernel. When an ADD_ADDR is retransmitted, the associated socket is not properly released, leading to a potential denial-of-service condition. The affected product is the Linux kernel, and the vulnerability class is a use-after-free error. The likely operational impact is a denial-of-service condition. The source-grounded technical framing is based on the official CVE Program record and the NIST NVD detail page. The patches are available to mitigate the vulnerability.

Defensive priority

Medium priority for Linux kernel maintainers and users, as the vulnerability requires local access and a specific configuration to exploit.

Recommended defensive actions

• Review and apply patches for the Linux kernel
• Monitor Linux kernel updates for potential vulnerabilities
• Consider implementing compensating controls for MPTCP
• 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
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability was introduced in the Linux kernel and has been resolved with patches available. The CVE record and NVD entry provide details on the affected versions and patches. The evidence is based on the official CVE Program record and the NIST NVD detail page. The affected scope is limited to the Linux kernel, and the patches are available for download. Defenders should verify the affected versions and apply the patches to mitigate the vulnerability.

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.