CVE-2026-98703 Linux CVE debrief

Who should care

Debian Linux kernel maintainers and users should assess exposure and verify Debian package versions. Additionally, Linux kernel maintainers, security teams, and operators should review the vulnerability's impact on their systems and configurations. They should verify Linux kernel versions and configurations to assess exposure and monitor for potential corruption of adjacent kernel memory. Restricting access to debugfs mounts to root-only users can help

Why it matters

A vulnerability in the Linux kernel's wifi: mac80211: minstrel_ht has been resolved, allowing any value to be written to the fixed_rate_idx debugfs file, leading to out-of-bounds array indexing and corruption of adjacent kernel memory.

• Verify Linux kernel versions and configurations to assess exposure.
• Restrict access to debugfs mounts to root-only users.
• Monitor for potential corruption of adjacent kernel memory.

Technical summary

The fixed_rate_idx debugfs file in the Linux kernel's wifi: mac80211: minstrel_ht module allows any u32 value to be written to it, which can lead to out-of-bounds array indexing and corruption of adjacent kernel memory. This issue is not a privilege boundary, but it is still a bug that must not be reachable through a writable debugfs attribute. The vulnerability has been resolved, but verifying Linux kernel versions and configurations is crucial to assess exposure. The issue affects the wifi: mac80211: minstrel_ht module, and

Defensive priority

Debian Linux kernel maintainers and users should assess exposure and verify Debian package versions.

Recommended defensive actions

• Assess exposure by verifying Linux kernel versions and configurations.
• Verify Debian package versions and apply updates if necessary.
• Monitor debugfs mounts and restrict access to root-only users.
• 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 vulnerability in the Linux kernel's wifi: mac80211: minstrel_ht module, which allows any u32 value to be written to the fixed_rate_idx debugfs file, leading to out-of-bounds array indexing and corruption of adjacent kernel memory. However, the scope of affected versions and systems requires verification, especially for Debian Linux kernel maintainers and users. To assess exposure, verify Linux kernel versions and configurations, and check relevant monitoring, detection, and logs for

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.