Out-of-bounds write in Linux kernel - CVE-2026-63960

 

Out-of-bounds write in Linux kernel - CVE-2026-63960

Published: July 20, 2026


Vulnerability identifier: #VU138697
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-2026-63960
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows an attacker with physical access to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in wcove_read_rx_buffer() when processing a crafted USB Power Delivery frame from a connected port partner. An attacker with physical access can transmit a crafted 31-byte frame to cause memory corruption.

The issue occurs on the IRQ thread stack, and the final register read may write past the end of struct pd_message.


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-2026-63960

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