Use of Uninitialized Variable in Linux kernel - CVE-2026-63837
Published: July 20, 2026
Vulnerability identifier: #VU138812
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63837
CWE-ID: CWE-457
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to use of uninitialized memory in ena_phc_gettimex64() when handling a PTP ioctl after ena_com_phc_get_timestamp() returns an error. A local user can invoke the affected ioctl to disclose sensitive information.
The issue can occur when PHC is disabled or in a blocked state, and invalid hardware values may also be exposed to userspace.
How to mitigate CVE-2026-63837
Install security update from vendor's repository.