CVE-2026-98590 Linux CVE debrief

Who should care

Linux kernel maintainers, administrators, and security teams should assess exposure and prioritize patching for affected systems. The vulnerability impacts Linux kernel maintainers, administrators, and security teams, who should assess exposure and prioritize patching for affected systems. Operators of Linux kernel-based systems, platform administrators, vulnerability management teams, and security teams should review the vulnerability and take necessary  

Why it matters

The Linux kernel vulnerability affects bpf sock context code generation, potentially leading to runtime values exceeding verifier expectations. Linux kernel maintainers, administrators, and security teams should assess exposure and prioritize patching for affected systems.

• Verify Linux kernel versions for potential exposure
• Assess and prioritize patching for affected systems
• Monitor system updates for Linux kernel fixes

Technical summary

The Linux kernel vulnerability involves incorrect bpf sock context code generation. The ctx access code reads the rx_queue_mapping field with either a 4-byte or 2-byte load. The rest of the bits in the register are marked known zero by the verifier. However, the emitted ctx access code places in the register on certain the special value (-1) using BPF_MOV_IMM64, which gets sign-extended to turn on all the bits in the register. By shifting this value right, the program ends up with a value at runtime above what the verifier assumes is possible.

Defensive priority

Verify Linux kernel versions and assess exposure; prioritize patching for affected systems.

Recommended defensive actions

• Verify Linux kernel versions for potential exposure
• Assess and patch affected systems
• Monitor system updates for Linux kernel fixes
• 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 CVE record and NVD entry provide details on the Linux kernel vulnerability. However, specific version impacts and exploitation details are not provided. The Linux kernel vulnerability affects bpf sock context code generation, potentially leading to runtime values exceeding verifier expectations. Linux kernel maintainers, administrators, and security teams should assess exposure and prioritize patching for affected systems. The vulnerability involves incorrect bpf sock context code generation. The ctx access code reads the rx_queue

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.