Out-of-bounds read in Linux kernel - CVE-2026-63943

Vulnerability identifier: #VU138713

CSH Severity: Medium

CVSS v4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-63943

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows an attacker with physical access to cause a denial of service.

The vulnerability exists due to an out-of-bounds read in xpadone_process_packet() when processing a crafted GIP_CMD_INPUT packet from a device. An attacker with physical access can supply a malformed controller packet with a short length to cause a denial of service.

The issue is triggered by a broken or malicious controller that controls both the reported packet length and packet contents.

Linux kernel
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/37ec54abfdd63a63fd50734a9c4e4cbc1e5795af
• https://git.kernel.org/stable/c/6346b0895b574ce45f3747b9c508c72f70e6abef
• https://git.kernel.org/stable/c/6cdc46b38cf146ce81d4831b6472dbf7731849a2
• https://git.kernel.org/stable/c/9749db57233b396353ad5dee81eec9d9880c9246
• https://git.kernel.org/stable/c/bcfb4833cd4078a1a356ef451838b75cd233099e

• Out-of-bounds read in Linux kernel input joystick driver
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia