SB2026091737 - Free of Memory not on the Heap in Linux kernel s390 kvm
Published: September 17, 2026
Security Bulletin ID
SB2026091737
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) Free of Memory not on the Heap (CVE-ID: CVE-2026-89920)
CWE-ID: CWE-590 - Free of Memory not on the Heap
CVSSv4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to improper freeing of stack memory in KVM s390 machine check reinjection when reinjecting channel-subsystem damage machine checks. A local user can trigger machine check reinjection to cause memory corruption.
Remediation
Install update from vendor's website.