SB20260815296 - Incorrect calculation in Linux kernel bpf



SB20260815296 - Incorrect calculation in Linux kernel bpf

Published: August 15, 2026

Security Bulletin ID SB20260815296
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) Incorrect calculation (CVE-ID: CVE-2026-72428)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: 4.8 [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]


The vulnerability allows a local user to bypass Spectre v4 sanitization checks.

The vulnerability exists due to improper index calculation in check_stack_write_fixed_off() in the BPF verifier when handling fixed-offset stack writes. A local user can trigger a crafted stack write pattern to bypass Spectre v4 sanitization checks.

The issue occurs because the sanitization pre-check examines different stack slot bytes than the write path updates.


Remediation

Install update from vendor's website.