Always-Incorrect Control Flow Implementation in Linux kernel - CVE-2026-23417
Published: April 3, 2026
Vulnerability identifier: #VU124855
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-23417
CWE-ID: CWE-670
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 bypass constant blinding in JIT-compiled BPF code.
The vulnerability exists due to improper handling of BPF_PROBE_MEM32 immediate stores in bpf_jit_blind_insn() when processing BPF programs for JIT compilation. A local user can supply a BPF program with user-controlled 32-bit immediates to bypass constant blinding in JIT-compiled BPF code.
The issue occurs when BPF_ST|BPF_MEM instructions are rewritten to BPF_ST|BPF_PROBE_MEM32 during verification before constant blinding runs, causing the immediate store instruction to fall through unblinded when JIT hardening is enabled.
How to mitigate CVE-2026-23417
Install security update from vendor's repository.