Improper input validation in Linux kernel - CVE-2026-98626

Vulnerability identifier: #VU156937

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98626

CWE-ID: CWE-20

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to bypass relocation-target validation and cause unintended replacement of BPF instructions.

The vulnerability exists due to improper validation of relocation targets before instruction poisoning in bpf_core_patch_insn(), shared by libbpf and in-kernel CO-RE, when processing unresolved CO-RE relocations. A local user can supply malformed relocation metadata targeting instructions that are not eligible for relocation to replace jumps, calls, exits, register-source arithmetic, or non-immediate loads instead of triggering a relocation error.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/2d7d04357c41aa49a5ac658fcc207439f2ad6456
• https://git.kernel.org/stable/c/394ae398337c5f87e567f6cd63b937fc2b2f6ddc
• https://git.kernel.org/stable/c/8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319
• https://git.kernel.org/stable/c/a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0
• https://git.kernel.org/stable/c/a8c47e62d9aea2d47a09e06c1682c59c21b92449
• https://git.kernel.org/stable/c/d3219c229d16900cef936adad28633c98946e432
• https://git.kernel.org/stable/c/f2a24101e89dd0804e717da7c1bd6af513698aa2

• Improper input validation in Linux kernel lib bpf
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more