CVE-2026-74690 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel-based systems, especially those utilizing ISM, should assess exposure and apply patches or updates as necessary. This includes Linux kernel developers, security teams, and system administrators managing Linux-based infrastructure. They should review system configurations, monitor logs for exploitation attempts, and prioritize patching based on asset criticality and potential impact. Additionally, they should conduct

Why it matters

CVE-2026-74690 is a high-severity use-after-free vulnerability in the Linux kernel's ISM subsystem. Defenders should prioritize patching affected systems to prevent potential system instability, unauthorized access, or denial-of-service attacks. Linux kernel maintainers have provided patches to address this issue.

• Potential system crashes or instability due to use-after-free memory access
• Possible elevation of privileges or unauthorized access
• Increased risk of denial-of-service (DoS) attacks
• Need for verification of Linux kernel versions and application of patches

Technical summary

The Linux kernel's ISM (Interrupt State Management) subsystem is vulnerable to a use-after-free issue. When ism_dev_exit() is called, it may run concurrently with an ISM interrupt handler, which can access freed data structures. This vulnerability has been addressed by draining ongoing interrupt handlers with free_irq() before freeing ISM data structures. The fix ensures that no new interrupts will be generated after unregister_ieq(), preventing potential system instability, unauthorized access, or denial-of-service attacks. Linux kernel maintainers have provided patches to address this high-severity issue, and defenders should prioritize verifying and applying these patches, especially in environments whereISM

Defensive priority

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments where ISM is utilized.

Recommended defensive actions

• Verify Linux kernel versions for potential exposure
• Apply patches or updates provided by the Linux kernel maintainers
• Review system configurations for ISM usage
• Monitor system logs for potential exploitation attempts
• Conduct vulnerability scanning to identify potentially affected systems
• Prioritize patching based on asset criticality and potential impact
• Implement compensating controls for exposed systems while remediation is scheduled

Evidence notes

The CVE record and associated source references indicate a use-after-free vulnerability in the Linux kernel's ISM subsystem. Official references from the Linux kernel Git repository confirm the vulnerability and its resolution.

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.