SB20261022211 - Improper input validation in Linux kernel lib bpf



SB20261022211 - Improper input validation in Linux kernel lib bpf

Published: October 22, 2026

Security Bulletin ID SB20261022211
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper input validation (CVE-ID: CVE-2026-98626)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 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]


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.


Remediation

Install update from vendor's website.