PT-2026-30123 · Linux · Linux Kernel

Published 2026-04-03 · Updated 2026-05-26 · CVE-2026-23428

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 7.0.0-rc3+

Description The Linux kernel contains a use-after-free flaw within the ksmbd component, specifically in how it handles share configurations during compound requests. The smb2 get ksmbd tcon() function reuses a tree connection (work->tcon) without validating its state, potentially leading to a dereference of freed memory if a prior command in a compound request (like SMB2 TREE DISCONNECT) has already disconnected the tree and freed the associated share conf. This can occur when the compound reuse path bypasses a necessary state check (t state == TREE CONNECTED) in ksmbd tree conn lookup(). A KASAN report indicates the issue occurs in the smb2 write function.

Recommendations Update to Linux kernel version 7.0.0-rc3+ or later.

Fix

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

CVE-2026-23428

ECHO-6130-AAB2-2C99

Affected Products

Linux Kernel

References · 19

• https://git.kernel.org/stable/c/eae0dc86f71e6f3294c0cd7ffc05039258d243af · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-23428 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-UBUNTU-2204-CVE-2026-23428 · Vendor Advisory
• https://git.kernel.org/stable/c/c33615f995aee80657b9fdfbc4ee7f49c2bd733d · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-23428 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-23428 · Security Note
• https://git.kernel.org/stable/c/a5929c2020ce54e1dcbd1078c0f30b8aaf73c105 · Patch
• https://git.kernel.org/stable/c/d08417981155883068b7260d9500ca306a03edac · Patch
• https://osv.dev/vulnerability/ROOT-OS-UBUNTU-2404-CVE-2026-23428 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-23428 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-23428 · Vendor Advisory
• https://git.kernel.org/stable/c/7f7468fd2a7554cea91b7d430335a3dbf01dcc09 · Patch
• https://ubuntu.com/security/CVE-2026-23428 · Vendor Advisory
• https://git.kernel.org/stable/c/806f13752652216db0c309392b4db3e64eeed4f2 · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-23428 · Vendor Advisory