Out-of-bounds write in Linux kernel - CVE-2026-64520
Published: July 27, 2026
Vulnerability identifier: #VU139410
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64520
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in the arm ffa partition information retrieval logic in drivers/firmware/arm_ffa/driver.c when processing firmware-provided partition descriptor indices in the register-based PARTITION_INFO_GET path. A local user can provide inconsistent descriptor counts or index progressions to cause a denial of service.
Exploitation requires interaction with untrusted or malformed firmware responses.
Affected software
Linux kernel
Ubuntu
linux-nvidia-6.17 (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
Ubuntu
linux-nvidia-6.17 (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
How to mitigate CVE-2026-64520
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1029.29
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1015.15, 7.0.0-1015.15~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1029.29
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1015.15, 7.0.0-1015.15~24.04.1