CVE-2026-46330 Linux CVE debrief

Who should care

Linux kernel maintainers, users, and administrators should assess exposure and apply patches to prevent potential use after free errors and system instability. Linux kernel versions 5.17 to 6.19.4 are affected. The vulnerability has a high CVSS score of 7.8 and is considered a high-severity vulnerability. Operators, platform administrators, and security teams should prioritize patching and review system configurations to ensure that affected versions are

Why it matters

CVE-2026-46330 is a high-severity vulnerability in the Linux kernel that requires immediate attention from maintainers and users. The vulnerability was caused by a design flaw in the TCP ULP support feature for SMC, which has been reverted. Linux kernel versions 5.17 to 6.19.4 are affected, and patches should be applied to prevent potential use after free errors and system instability.

• Verify Linux kernel versions and configurations to ensure patches are applied.
• Monitor system stability and review logs for potential use after free errors.
• Assess exposure and prioritize patching for Linux kernel versions 5.17 to 6.19.4.

Technical summary

The Linux kernel vulnerability (CVE-2026-46330) was caused by a design flaw in the TCP ULP support feature for SMC. The implementation attempted to modify the underlying `struct file`, dentry, and inode in-place, violating core VFS invariants. This flaw could lead to use after free errors and general system instability. The feature has been reverted as a result. Linux kernel versions 5.17 to 6.19.4 are affected, and patches should be applied to prevent potential use after free errors and system instability. The vulnerability has a high CVSS score of 7.8 and is considered a high-severity vulnerability.

Defensive priority

High priority for Linux kernel maintainers and users to assess exposure and apply patches.

Recommended defensive actions

• Assess exposure and apply patches for Linux kernel versions 5.17 to 6.19.4.
• Review system configurations and ensure that affected versions are identified and updated.
• Monitor system stability and review logs for potential use after free errors.
• Verify Linux kernel versions and configurations to ensure patches are applied.
• Assess exposure and prioritize patching for Linux kernel versions 5.17 to 6.19.4.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. Linux kernel versions 5.17 to 6.19.4 are affected. The vulnerability was caused by a design flaw in the TCP ULP support feature for SMC, which has been reverted. The implementation attempted to modify the underlying `struct file`, dentry, and inode in-place, violating core VFS invariants. This flaw could lead to use after free errors and general system instability. Verify Linux kernel versions and ensure the

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.