SB20260812406 - Improper access control in Linux kernel smb server
Published: August 12, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper access control (CVE-ID: CVE-2026-68130)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper access control in ntlm_authenticate() when processing an NTLM authentication request containing a crafted username field and PreviousSessionId. A remote user can supply a username matching a victim account and a victim session identifier to cause a denial of service.
The issue can destroy another user's SMB session before the NTLMv2 response is validated.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/0ff12308c8a6c16ab68f0a487ffa93d69001dc18
- https://git.kernel.org/stable/c/18705cace0619fd2123737dcd028147774f38181
- https://git.kernel.org/stable/c/243f1614ef2aca2d62a744575f1c24b07cd42757
- https://git.kernel.org/stable/c/5c833074b549e5db125436a6f681af682261f785
- https://git.kernel.org/stable/c/c74801ee524f477c174a1899782b6c3b6918d407