SB20260912146 - Use of cache containing sensitive information in Linux kernel smb client
Published: September 12, 2026
Security Bulletin ID
SB20260912146
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use of cache containing sensitive information (CVE-ID: CVE-2026-89639)
CWE-ID: CWE-524 - Use of Cache Containing Sensitive Information
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose stale cached data.
The vulnerability exists due to improper cache invalidation in cifs_do_truncate() in the SMB client when truncating a file with O_TRUNC. A local user can trigger file truncation to disclose stale cached data.
The stale data can be served after the cache cookie is activated.
Remediation
Install update from vendor's website.