CVE-2026-90067 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel security, particularly in environments using Ceph, should assess exposure and prioritize patching. This includes operators, platform administrators, vulnerability management teams, and security teams who need to review and update Ceph configurations to ensure secure protocol implementation. They should also monitor for potential protocol errors and warnings in kernel logs, and perform vulnerability scanning toidentify

Why it matters

A vulnerability in the Linux kernel's Ceph messenger v2 protocol implementation can cause a 0-length socket read when a client sends a banner with an invalid payload length, triggering a warning and potentially leading to a protocol error.

• Verify and prioritize patching for Linux kernel versions affected by this vulnerability
• Review and update Ceph configurations to ensure secure protocol implementation
• Monitor for potential protocol errors and warnings in kernel logs

Technical summary

The Linux kernel's Ceph messenger v2 protocol implementation is vulnerable to a 0-length socket read when a client sends a banner with an invalid payload length. This issue has been resolved by adding a check to reject payload lengths smaller than 16 bytes. The vulnerability affects Linux kernel versions and could lead to protocol errors if exploited. Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments using Ceph. The fix prevents the 0-length read and correctly aborts the connection with a protocol error.

Defensive priority

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments using Ceph.

Recommended defensive actions

• Verify and apply patches for Linux kernel versions affected by this vulnerability
• Review and update Ceph configurations to ensure secure protocol implementation
• Monitor for potential protocol errors and warnings in kernel logs
• Perform vulnerability scanning to identify affected systems
• Implement compensating controls for exposed systems
• Review asset inventory for affected components
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and associated sources provide details on the vulnerability, including its description, CVSS score, and affected components. However, specific version information and exploitation details are not provided.

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.