SB20261007197 - Use-after-free in Linux kernel smb client



SB20261007197 - Use-after-free in Linux kernel smb client

Published: October 7, 2026

Security Bulletin ID SB20261007197
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-98171)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 0 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to trigger access to freed memory.

The vulnerability exists due to use-after-free in the SMB client's receive_encrypted_standard() function when handling compound encrypted frames and subsequent error paths. A remote attacker can supply compound encrypted frames that encounter an error after buffer reassignment to trigger access to freed memory.

The next_buffer pointer remains stale after its buffer is assigned to server->bigbuf.


Remediation

Install update from vendor's website.