CVE-2026-74660 Linux CVE debrief

Who should care

Linux system administrators, security teams, and developers using ebt_nflog in their deployments should assess exposure and prioritize patching. They should review and apply patches from Linux vendors for the affected kernel versions, inventory Linux systems using ebt_nflog, and monitor for potential exploitation attempts targeting this vulnerability. Additionally, they should review compensating controls for exposed systems while remediation is scheduled,

Why it matters

This vulnerability in the Linux kernel's netfilter ebt_nflog component can lead to system instability, potential privilege escalation, and requires verification of logger module usage and patching.

• Potential system crashes or instability due to use-after-free conditions.
• Possible elevation of privileges or unauthorized access.
• Required verification of logger module usage and ebt_nflog rule configurations.
• Necessity to review and apply patches from Linux vendors.

Technical summary

The Linux kernel's netfilter ebt_nflog component is vulnerable to a use-after-free condition. ebt_nflog does not hold a reference to the selected logger module when passing an explicit ULOG log type to nf_log_packet(). This allows the logger module to be unloaded while ebt_nflog rules remain callable, leading to potential use-after-free conditions when accessing the logger. The vulnerability was introduced due to ebt_nflog passing an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module. This issue was fixed in various Linux kernel commits. The vulnerability can cause system instability, potential privilege escalation, and requires verification of logger module

Defensive priority

High

Recommended defensive actions

• Review and apply patches from Linux vendors for the affected kernel versions.
• Inventory Linux systems using ebt_nflog and assess exposure.
• Monitor for potential exploitation attempts targeting this vulnerability.
• 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 vulnerability was introduced due to ebt_nflog passing an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module. This issue was fixed in various Linux kernel commits.

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.