CVE-2026-74736 Linux CVE debrief

Who should care

Linux administrators and users, network administrators, security teams, operators managing Linux-based systems, vulnerability management teams, and platform security teams responsible for Linux kernel updates and configurations across various environments and infrastructures.

Why it matters

This vulnerability in the Linux kernel's cls_bpf implementation could lead to denial of service or potentially allow for arbitrary code execution with elevated privileges. Linux administrators and users, network administrators, and security teams should assess exposure, prioritize patching, and monitor for suspicious activity.

• Denial of service due to potential netdevsim WARN or panic
• Potential for elevated privilege execution
• Need for verification of affected systems and application of patches
• Importance of monitoring system logs for suspicious events

Technical summary

The Linux kernel's cls_bpf implementation did not properly verify that a device-bound program's bound netdev matches the TC netdev the classifier is being attached to. This oversight could lead to a program loaded for one device being attached to another, potentially causing issues when the first device is deleted. The improper handling of device-bound programs bound to a different device could allow a locally authenticated attacker to cause a denial of service or potentially execute arbitrary code with elevated privileges. The issue arises from the lack of verification between the device-bound program's netdev and the TC netdev during the attachment process via cls_bpf + skip_sw. This could result in the offlo

Defensive priority

Medium

Recommended defensive actions

• Review and apply available patches to Linux kernel
• Verify affected systems are updated to a fixed version
• Monitor system logs for potential denial-of-service or elevated privilege events
• Conduct a thorough review of system configurations and network setups
• Inventory and assess all systems using the Linux kernel for exposure
• Implement compensating controls for exposed systems while remediation is scheduled
• Track and document remediation progress and verification efforts

Evidence notes

The CVE record and associated source item provide details about the vulnerability, including its description, affected versions, and references to relevant commits. However, there is limited information about potential exploits or attacks in the wild.

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.