SB2026073030 - Improper input validation in Linux kernel s390 crypto driver
Published: July 30, 2026
Security Bulletin ID
SB2026073030
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-64559)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code or cause a denial of service.
The vulnerability exists due to improper input validation in the PKEY_VERIFYPROTK ioctl in drivers/s390/crypto/pkey_api.c when processing a user-supplied request structure from user space. A local user can provide a crafted buffer length value to execute arbitrary code or cause a denial of service.
Remediation
Install update from vendor's website.