Vulnerability in Linux

[ Description ]Official 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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund28 Oct 2026WID-SEC-2026-4224

  Linux Kernel: Multiple vulnerabilities allow an unspecified attack Translated from German

  CVE-2026-99116CVE-2026-99143CVE-2026-99170+113 more CVEs

[ References ]References

• git.kernel.org/stable/c/1525fb6e2f9f9a2c8c8723ee0959b1130a6b8213
• git.kernel.org/stable/c/34fa3607b7604b3052b19cec8b0ad644818cdd2a
• git.kernel.org/stable/c/8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab
• git.kernel.org/stable/c/977dac6cc5531a8e058df05b6af94406b940cb9e
• git.kernel.org/stable/c/a7c3e1795e4fe5e6680cab7cd7eee0503b00a248
• git.kernel.org/stable/c/b264d8422779d69febce914efc47a92a85cc382c
• git.kernel.org/stable/c/c11e435d334e4c311eaaf721e179a5ca6852c221
• git.kernel.org/stable/c/f9d9e2dadc9fbdfe01aeb6581978c3b59092919e