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CVE-2026-43333

Updated on 08 May 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE ID
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

bpf: reject direct access to nullable PTR_TO_BUF pointers

check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check.

Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference.

Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern.

Details

Affected product:
AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
Affected packages:
kernel @ 4.18.0 (+6 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Amazon Linux 2023 Planned —
Debian 13 Planned —
Ubuntu 22.04 Planned —
Ubuntu 24.04 Released
46 kernels
  • 6.8.0-35.35
  • 6.8.0-38.38
  • 6.8.0-36.36
  • 6.8.0-39.39
  • 6.8.0-40.40
  • 6.8.0-41.41
  • 6.8.0-44.44
  • 6.8.0-45.45
  • 6.8.0-31.31
  • 6.8.0-47.47
  • 6.8.0-48.48
  • 6.8.0-49.49
  • 6.8.0-50.51
  • 6.8.0-51.52
  • 6.8.0-52.53
  • 6.8.0-54.56
  • 6.8.0-55.57
  • 6.8.0-53.55
  • 6.8.0-56.58
  • 6.8.0-57.59
  • 6.8.0-58.60
  • 6.8.0-59.61
  • 6.8.0-60.63
  • 6.8.0-62.65
  • 6.8.0-63.66
  • 6.8.0-64.67
  • 6.8.0-71.71
  • 6.8.0-78.78
  • 6.8.0-79.79
  • 6.8.0-84.84
  • 6.8.0-85.85
  • 6.8.0-83.83
  • 6.8.0-86.87
  • 6.8.0-87.88
  • 6.8.0-88.89
  • 6.8.0-90.91
  • 6.8.0-94.96
  • 6.8.0-100.100
  • 6.8.0-101.101
  • 6.8.0-106.106
  • 6.8.0-107.107
  • 6.8.0-110.110
  • 6.8.0-111.111
  • 6.8.0-117.117
  • 6.8.0-124.124
  • 6.8.0-134.134