PT-2026-38984 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-16 · CVE-2026-43333

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the BPF subsystem where the check mem access() function matches PTR TO BUF via base type(), which strips PTR MAYBE NULL. This allows direct dereference of pointers without a null check. Specifically, map iterator ctx->key and ctx->value are marked as PTR TO BUF | PTR MAYBE NULL. During stop callbacks, these can be NULL, leading to a kernel NULL dereference (a situation where the system attempts to read or write to a memory address of zero, typically resulting in a system crash).

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2026-43333

Affected Products

Linux Kernel

References · 19

• https://osv.dev/vulnerability/BELL-CVE-2026-43333 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43333 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43333 · Security Note
• https://git.kernel.org/stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43333 · Vendor Advisory
• https://git.kernel.org/stable/c/b0db1accbc7395657c2b79db59fa9fae0d6656f3 · Patch
• https://git.kernel.org/stable/c/10bc4a4dcded509c5d5c67d497900c3922c604cd · Patch
• https://git.kernel.org/stable/c/4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09 · Patch
• https://git.kernel.org/stable/c/70abd9d118da2f56beb4ec22e3a29becae373535 · Patch
• https://cve.org/CVERecord?id=CVE-2026-43333 · Security Note
• https://git.kernel.org/stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43333 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-43333 · Vendor Advisory
• https://git.kernel.org/stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56 · Patch
• https://t.me/cveNotify/163675 · Telegram Post