CVE-2025-39806

A flaw exists in the Linux kernel’s HID multitouch driver (function mt_report_fixup() in drivers/hid/hid-multitouch.c). A malicious HID device may supply a report descriptor smaller than 607 bytes; the function then attempts to access and patch byte offset 607 without first verifying the descriptor length. This can lead to a slab out-of-bounds access, potentially resulting in memory corruption or a denial of service

This vulnerability is rated as Moderate severity because exploitation necessitates local interaction with a crafted hardware or emulated USB input device, limiting the attack vector compared to remotely exploitable flaws. In standard Red Hat Enterprise Linux server environments, physical access to attach malicious peripherals is strictly controlled, and multitouch devices are typically not utilized. While the out-of-bounds access can cause a kernel crash or potential local privilege escalation upon device enumeration, systems that do not accept untrusted HID devices or virtual machine passthrough remain insulated from external exposure.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.