SB20261029188 - NULL pointer dereference in Linux kernel s390 net driver
Published: October 29, 2026
Security Bulletin ID
SB20261029188
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) NULL pointer dereference (CVE-ID: CVE-2026-99126)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 a null pointer dereference in the Linux kernel s390 CTCM driver's mpc_validate_xid() function when validating a null peer XID or handling a read/write channel pairing mismatch. A local user can trigger these validation error conditions to cause access to the uninitialized grp->saved_xid2 pointer, potentially crashing the kernel.
Remediation
Install update from vendor's website.