SB20260815296 - Incorrect calculation in Linux kernel bpf
Published: August 15, 2026
Breakdown by Severity
- 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.
References
- https://git.kernel.org/stable/c/475405593de2b796224c6297aece44f321195919
- https://git.kernel.org/stable/c/68b41e68a62299f26cb16af422b5c7d1c69dafd9
- https://git.kernel.org/stable/c/a71eb8f730a91271cf47ce291e785b6b7e54622f
- https://git.kernel.org/stable/c/ca119656baa8f48a56e0c2f3ab63fdd33ca9e307
- https://git.kernel.org/stable/c/d1d53aa30ab3b5ae89161c9cc840b3f7489ad386
- https://git.kernel.org/stable/c/db8f1dcf5950b91886b9df4270bc816370d292c1
- https://git.kernel.org/stable/c/e62268e695075a481a6c4feeb022c19cf57422a6
- https://git.kernel.org/stable/c/f1471aa76d74e0df3b2a90731ca0208f498c670b