CVE-2026-99037 Linux CVE debrief

Who should care

Linux system administrators, security teams, and users of Linux-based systems should be aware of this vulnerability and take steps to verify their system configurations and apply patches as needed.

Why it matters

CVE-2026-99037 is a Linux kernel vulnerability that can cause a denial of service due to memory corruption when using the lmk IV mode with AEAD ciphers in dm-crypt. Linux system administrators and security teams should verify system configurations and apply patches to prevent potential issues.

• Denial of service due to memory corruption
• Potential system crashes or instability
• Need for patching and verification of Linux kernel versions

Technical summary

The Linux kernel vulnerability CVE-2026-99037 is caused by the lmk IV mode being used with AEAD ciphers in dm-crypt, leading to memory corruption. This issue can be triggered by a root user and results in a denial of service. The vulnerability is addressed through a series of patches that reject the lmk IV mode with AEAD ciphers. Linux system administrators and security teams should verify system configurations and apply patches to prevent potential issues. The vulnerability does not lead to arbitrary code execution or data theft, but it can cause system crashes or instability.

Defensive priority

Medium

Recommended defensive actions

• Review Linux kernel versions and apply patches to reject lmk IV mode with AEAD ciphers in dm-crypt
• Monitor for updates from Linux kernel maintainers regarding this vulnerability
• Verify system configurations to prevent potential denial of service
• Perform a thorough review of system configurations to identify potential exposures
• Implement compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions and retest remediated assets
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source item provide details about the vulnerability, including its description, affected versions, and references to source code patches. However, there is limited information about potential exploits or victim impact.

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.