CVE-2026-90025 Linux CVE debrief

Who should care

Linux system administrators, kernel developers, and users of Linux distributions should assess exposure and apply patches to prevent potential system crashes. Linux kernel developers and maintainers should review and update the UCSI displayport driver to fix the vulnerability. Additionally, security teams and vulnerability management teams should monitor Linux kernel updates and track CVE-2026-90025 for further information.

Why it matters

CVE-2026-90025 is a Linux kernel vulnerability in the UCSI displayport driver that allows an out-of-bounds array index error, potentially leading to a kernel crash. Linux system administrators and kernel developers should assess exposure and apply patches.

• Verify patch deployment to prevent potential system crashes
• Assess Linux kernel versions for vulnerability and apply updates
• Monitor system logs for potential exploitation attempts

Technical summary

The Linux kernel vulnerability CVE-2026-90025 is caused by an out-of-bounds array index error in the UCSI displayport driver. The driver incorrectly accesses the port altmode array using a GET_CURRENT_CAM response that exceeds the array bounds, potentially leading to a kernel crash. The vulnerability is triggered when the PPM returns an invalid GET_CURRENT_CAM response above UCSI_MAX_ALTMODES and not equal to 0xff. To fix this issue, the UCSI displayport driver should verify the current cam is less than UCSI_MAX_ALTMODES before accessing the port altmode array.

Defensive priority

Verify and apply patches for Linux kernel versions affected by CVE-2026-90025, particularly for systems utilizing the UCSI displayport driver.

Recommended defensive actions

• Review Linux kernel versions and apply patches to fix the OOB altmode array index vulnerability
• Verify system configurations and update UCSI displayport driver to prevent potential crashes
• Monitor Linux kernel updates and track CVE-2026-90025 for further information
• Verify patch deployment to prevent potential system crashes
• Assess Linux kernel versions for vulnerability and apply updates
• Monitor system logs for potential exploitation attempts
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and associated source references provide details on the vulnerability, including its cause, potential impact, and fixed versions. However, specific exploitation instances or victim information are not provided.

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.