Use of Uninitialized Variable in Linux kernel - CVE-2026-64082
Published: July 20, 2026
Vulnerability identifier: #VU138563
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64082
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 corrupt register state and disclose kernel stack contents.
The vulnerability exists due to use of uninitialized stack data in compat_riscv_gpr_set() and compat_restore_sigcontext() when handling failed user memory copies. A local user can provide crafted user-supplied register or signal context data that triggers a copy failure to corrupt register state and disclose kernel stack contents.
The issue affects the RISC-V compatibility signal and ptrace handling paths.
How to mitigate CVE-2026-64082
Install security update from vendor's repository.