SB2026102379 - Out-of-bounds write in Linux kernel smb server

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Main Vulnerability Database SB2026102379

SB2026102379 - Out-of-bounds write in Linux kernel smb server

Published: October 23, 2026

Security Bulletin ID SB2026102379
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2026-99083)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to corrupt kernel heap memory and potentially cause a denial of service.

The vulnerability exists due to an out-of-bounds write in the Linux kernel ksmbd krb5_authenticate() function when processing SMB2_SESSION_SETUP as a non-first element of a compounded SMB2 request. A remote attacker can send a specially crafted compounded request to trigger an overstated response buffer capacity calculation, allowing a Kerberos AP-REP token to be copied beyond response_buf into adjacent kernel heap memory.


Remediation

Install update from vendor's website.

References