NULL pointer dereference in Linux kernel - CVE-2026-99126
Published: October 29, 2026
Vulnerability identifier: #VU158463
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-99126
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-99126
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.115-2
linux (Debian package) - update to 6.12.115-2