SB2026072087 - Race condition in Linux kernel smb client
Published: July 20, 2026
Security Bulletin ID
SB2026072087
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Race condition (CVE-ID: CVE-2026-64136)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper synchronization in smb2_find_smb_sess_tcon_unlocked() when handling SMB tree connection lookups. A local user can trigger concurrent access to corrupt tc_count handling and cause a denial of service.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7
- https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41
- https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d
- https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a
- https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd