CVE-2023-3866: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 11.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate session id and tree id in the compound request This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error.

Affected products

• Linux Linux Kernel: from 5.15, before 5.15.121 (fixed in 5.15.121); from 5.16, before 6.1.36 (fixed in 6.1.36); from 6.2, before 6.3.10 (fixed in 6.3.10); version 6.4 only

Published 2025-08-16. Last modified 2026-08-04.