CVE-2026-98623 Linux CVE debrief

Who should care

Linux kernel maintainers, Linux distribution maintainers, and users of systems with the nouveau driver should assess their exposure and verify the presence of the fix. Additionally, security teams and vulnerability management teams should review the impact of this vulnerability on their organization's assets and prioritize remediation efforts accordingly.

Why it matters

A vulnerability in the Linux kernel's drm/nouveau/clk component has been resolved, potentially leading to an out-of-bounds read when an invalid pstate ID is requested. Linux kernel maintainers and users should assess exposure and verify the presence of the fix.

• Verify Linux kernel versions and apply updates to prevent potential out-of-bounds reads
• Assess exposure in systems using the nouveau driver
• Review and update defensive configurations for Linux kernel components

Technical summary

The nvkm_clk_ustate_update function in the Linux kernel's drm/nouveau/clk component has been fixed to properly handle list cursor usage after a loop. An out-of-bounds read could occur when an invalid pstate ID is requested, potentially through the 'pstate' debugfs file. This issue affects Linux kernel versions that include the nouveau driver. Maintainers and users should assess exposure and verify the presence of the fix, particularly in systems using the nouveau driver, to prevent potential out-of-bounds reads. The fix involves introducing a 'found' variable to track the validity of the pstate pointer.

Defensive priority

Linux kernel maintainers and users should assess exposure and verify the presence of the fix, particularly in systems using the nouveau driver.

Recommended defensive actions

• Review Linux kernel updates and apply the fix for the drm/nouveau/clk component
• Verify the presence of the fix in Linux kernel versions
• Assess exposure in systems using the nouveau driver
• Perform vulnerability scanning to identify potentially affected systems
• Implement compensating controls for exposed systems while remediation is scheduled
• Monitor relevant logs for signs of exploitation on exposed assets
• Track exceptions and retest remediated assets to ensure fix effectiveness

Evidence notes

The CVE record and associated source references provide details on the vulnerability and its resolution. However, the impact and affected versions require further verification from official Linux kernel 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.