CVE-2026-90300 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, system administrators responsible for Linux kernel updates and security patches, and security teams monitoring Linux kernel vulnerabilities.

Why it matters

A vulnerability in the Linux kernel's bpf subsystem can lead to issues with deterministic buffer contents. Linux kernel developers and maintainers, system administrators, and security teams should verify Linux kernel versions, apply security patches, and monitor updates to address this vulnerability.

• Verify Linux kernel versions to identify potentially vulnerable systems
• Apply security patches to ensure buffer clearing on error in __bpf_get_task_stack
• Monitor Linux kernel updates for security patches

Technical summary

The Linux kernel's bpf subsystem has a vulnerability in the __bpf_get_task_stack function where a buffer is not cleared on error. This can lead to issues with deterministic buffer contents. The vulnerability is addressed in specific commits. The __bpf_get_task_stack function is used to retrieve the task stack, and the buffer clearing issue on error can impact the reliability and security of systems using the affected Linux kernel versions. Linux kernel developers and maintainers, system administrators responsible for Linux kernel updates and security patches, and security teams monitoring Linux kernel vulnerabilities should verify Linux kernel versions, apply security patches, and monitor updates to address

Defensive priority

Verify Linux kernel versions and apply patches to ensure buffer clearing on error in __bpf_get_task_stack.

Recommended defensive actions

• Verify Linux kernel versions and apply patches to ensure buffer clearing on error in __bpf_get_task_stack.
• Review system configurations and inventory to identify potentially affected systems.
• Monitor Linux kernel updates and apply security patches promptly.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and source item provide details on the vulnerability and affected Linux kernel versions. Specific commits address the issue. The buffer clearing issue on error in __bpf_get_task_stack can lead to unpredictable behavior in systems using the affected Linux kernel versions. Defenders should verify Linux kernel versions, review system configurations and inventory to identify potentially affected systems, and monitor Linux kernel updates for security patches. The vulnerability is addressed in specific commits, and defenders

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.