Out-of-bounds write in Linux kernel - CVE-2026-64558
Published: July 30, 2026
Vulnerability identifier: #VU140098
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64558
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to an out-of-bounds write in the pkey_pckmo key_to_protkey() handler implementation when processing a target buffer for generated output data. A local user can provide a target buffer with an insufficient length to execute arbitrary code.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-64558
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.100-1
linux (Debian package) - update to 6.12.100-1