Microsoft Security Response Center guidance
Vendor revision: Oct 29, 2026Release Notes
Vulnerability intelligence
CVE-2026-99126. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
In the Linux kernel, the following vulnerability has been resolved:
s390/ctcm: Prevent XID null dereference
The mpc_validate_xid() function sets grp->saved_xid2->xid2_flag2 to 0x40 to signal XID validation error. If peer XID is NULL or r/w channel pairing mismatch happens, grp->saved_xid2 is never initialized.
An attempt to set the flag in such case leads to NULL dereference.
Fix this by using the always available priv->xid->xid2_flag2 instead of grp->saved_xid2->xid2_flag2 for validation errors.
Source: NVD