Out-of-bounds read in Linux kernel - CVE-2026-63961

 

Out-of-bounds read in Linux kernel - CVE-2026-63961

Published: July 20, 2026


Vulnerability identifier: #VU138681
CSH Severity: Low
CVSS v4: 2.4 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63961
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows an attacker with physical access to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in the DisplayPort altmode handler when processing a malformed Status Update VDO from a connected USB Type-C device. An attacker with physical access can send a device response with an incorrect VDO count to disclose sensitive information.

The issue can cause the kernel to read uninitialized stack data and forward it elsewhere.


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-2026-63961

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