SB2026073029 - Out-of-bounds write in Linux kernel s390 crypto driver
Published: July 30, 2026
Security Bulletin ID
SB2026073029
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) Out-of-bounds write (CVE-ID: CVE-2026-64558)
CWE-ID: CWE-787 - Out-of-bounds write
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.
The vulnerability exists due to an out-of-bounds write in the pkey_pckmo key_to_protkey() handler implementation when processing a target buffer for generated output data. A local user can provide a target buffer with an insufficient length to execute arbitrary code.
Remediation
Install update from vendor's website.