CVE-2026-99126

medium

Description

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.

References

https://git.kernel.org/stable/c/b264d8422779d69febce914efc47a92a85cc382c

https://git.kernel.org/stable/c/8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab

https://git.kernel.org/stable/c/34fa3607b7604b3052b19cec8b0ad644818cdd2a

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-111878

Details

Source: Mitre, NVD

Published: 2026-10-28

Updated: 2026-10-28

Risk Information

CVSS v2

Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00167