PT-2026-27651 · Linux · Linux Kernel

Published 2026-01-01 · Updated 2026-04-20 · CVE-2026-23286

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 The Linux kernel's ATM LANE (LAN Emulation) module contains a null pointer dereference issue in the lec arp clear vccs() function. This flaw occurs when the underlying Virtual Circuit (VCC) is closed and the function is called multiple times for ARP entries sharing the same VCC. Specifically, after the associated vpriv (which is vcc->user back) is freed in the first iteration, a subsequent iteration attempts to dereference a NULL vpriv obtained from vcc->user back via LEC VCC PRIV(vcc), leading to a crash. The issue affects both the entry->vcc and entry->recv vcc paths, with the latter added in a later commit.

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

Exploit

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2026-23286

ECHO-E844-4DA2-F4E8

Affected Products

Linux Kernel

References · 22

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23286.json · Exploit
• https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb · Patch
• https://ubuntu.com/security/CVE-2026-23286 · Vendor Advisory
• https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875 · Patch
• https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e · Patch
• https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-23286 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-23286 · Security Note
• https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-23286 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-23286 · Vendor Advisory
• https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665 · Patch
• https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da · Patch
• https://osv.dev/vulnerability/ROOT-OS-UBUNTU-2404-CVE-2026-23286 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2026-23286 · Vendor Advisory