Out-of-bounds read in Linux kernel - CVE-2026-64000

Vulnerability identifier: #VU138652

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64000

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an out-of-bounds read in supervision frame handling in net/hsr/hsr_forward.c when processing truncated supervision frames. A remote attacker can send a specially crafted frame to cause a denial of service.

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/09a37dca090c55ffb1a33f52d8667f1c2367ef48
• https://git.kernel.org/stable/c/71c986c0ba45b7dc574fae27c83e7b6671556f37
• https://git.kernel.org/stable/c/78607a6854a22a2502f68092202e75a39af4865d
• https://git.kernel.org/stable/c/a4b64f3e9c7b8259f7dd251a0313420ba7c01852
• https://git.kernel.org/stable/c/f229426072fc865654a60978bb7fda790a051ff3
• https://git.kernel.org/stable/c/fbd0662f9c9a66e8cc3df3099cca8ed6d3837cc7

• Out-of-bounds read in Linux kernel hsr
• 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