Out-of-bounds write in Linux kernel - CVE-2026-63908

 

Out-of-bounds write in Linux kernel - CVE-2026-63908

Published: July 20, 2026


Vulnerability identifier: #VU138744
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63908
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to overwrite adjacent memory.

The vulnerability exists due to an out-of-bounds write in mxt_prepare_cfg_mem in the atmel_mxt_ts driver when parsing a crafted configuration file with an object size larger than the expected object size. A local user can provide a specially crafted configuration file to overwrite adjacent memory.

The issue is caused by an incorrect boundary check on a 0-based index, which allows exactly one byte past the valid object boundary to be written.


Affected software

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

How to mitigate CVE-2026-63908

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

External References

Related Security Bulletins