CVE-2026-93125 Linux CVE debrief

Who should care

Linux kernel developers, administrators, and security teams should assess exposure and prioritize verification of affected systems, especially those with BPF or kernel module usage.

Why it matters

A vulnerability in the Linux kernel's BPF subsystem can cause incorrect verifier behavior, potentially leading to security issues. Linux kernel developers and administrators should assess exposure and prioritize verification of affected systems.

• Verification of BPF-based security mechanisms is required to ensure correct functionality.
• Potential incorrect access checks may occur due to the verifier's incorrect memory size recording.
• Linux kernel developers and administrators should prioritize patching or mitigating affected systems.

Technical summary

The Linux kernel's BPF subsystem has a vulnerability where the verifier incorrectly records memory size for pointers due to improper bounding of rdonly_buf_size or rdwr_buf_size argument values. This issue has been resolved by rejecting values exceeding U32_MAX. Affected Linux kernel developers and administrators should assess exposure, prioritize verification of affected systems, especially those with BPF or kernel module usage, and consider implementing compensating controls for BPF-based security mechanisms. The flaw arises from the check_kfunc_args() function not properly bounding the rdonly_buf_size or rdwr_buf_size argument values for certain kfuncs, which can result in a u64 value being truncated when

Defensive priority

Linux kernel developers and administrators should assess exposure and prioritize verification of affected systems, especially those with BPF or kernel module usage.

Recommended defensive actions

• Review Linux kernel configurations and BPF usage to identify potential exposure
• Verify system updates and patches for the Linux kernel
• Monitor system logs for suspicious BPF activity
• Consider implementing compensating controls for BPF-based security mechanisms
• Perform vulnerability scanning to identify potentially affected assets
• Implement asset inventory management to track affected systems
• Establish a rollback change window for remediation

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and CVSS score. However, specific version information and exploitation details are not provided, requiring further verification.

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.