CVE-2026-90372 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel-based systems, especially those using the affected mt76 driver versions, should assess their exposure and prioritize patching. This includes reviewing system configurations, inventory, and monitoring for potential exploitation attempts. Vulnerability management and security teams should verify and apply patches, and implement compensating controls for exposed systems.

Why it matters

The CVE-2026-90372 vulnerability in the Linux kernel's mt76 driver requires verification and patching to prevent potential exploitation. Defenders should prioritize patching and assess exposure in their Linux kernel-based systems.

• Verify and prioritize patching for Linux kernel versions using the affected mt76 driver
• Assess exposure in Linux kernel-based systems using the mt76 driver
• Monitor for potential exploitation attempts targeting the vulnerability

Technical summary

The vulnerability occurs in the `mt7915_mcu_get_sta_nss` function of the Linux kernel's mt76 driver. A peer's VHT/HE MCS map with no supported spatial stream can cause an underflow in the `nss` variable, leading to an invalid value being written to the firmware's `sta_rec_bf` beamforming fields. The issue has been resolved with a patch that clamps the result to 0. Defenders should prioritize verifying and applying patches for this vulnerability, especially in systems using the affected Linux kernel versions. The patch prevents the underflow by ensuring the `nss` value does not go below 0.

Defensive priority

Defenders should prioritize verifying and applying patches for this vulnerability, especially in systems using the affected Linux kernel versions.

Recommended defensive actions

• Verify and apply patches for the Linux kernel's mt76 driver vulnerability
• Review system configurations and inventory for potential exposure
• Monitor for potential exploitation attempts
• Perform thorough vulnerability assessments
• Implement compensating controls for exposed systems
• Track exceptions and retest remediated assets
• Review relevant monitoring, detection, and logs for exposed assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and vector. However, the exact scope of affected systems and versions requires further verification from official sources.

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.