Incorrect calculation in Linux kernel - CVE-2026-72428

Vulnerability identifier: #VU143015

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2026-72428

CWE-ID: CWE-682

Exploitation vector: Local access

Exploit availability: No public exploit available

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.

Linux kernel
Ubuntu
linux-nvidia (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• 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

• Incorrect calculation in Linux kernel bpf
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0