Linux Kernel ksmbd EUVD-2026-28685

Upgrade to patched Linux kernel versions: 6.6.130+ for 6.6.x series, 6.12.78+ for 6.12.x, 6.18.19+ for 6.18.x, 6.19.9+ for 6.19.x, or 7.0+ for latest mainline. Patches available via standard kernel update mechanisms for major distributions (apt, yum, dnf). Verify fix application by checking kernel version with 'uname -r' and confirming commit presence with 'git log' if building from source. For systems that cannot immediately patch: disable ksmbd module if not required ('rmmod ksmbd' and blacklist in /etc/modprobe.d/); if SMB server functionality is required, migrate to userspace Samba server which is unaffected by this kernel vulnerability; restrict network access to ksmbd service (TCP ports 445, 139) to trusted networks only via firewall rules as compensating control, though this does not eliminate risk from internal threats or compromised trusted systems. Note that disabling ksmbd will interrupt SMB file sharing services; plan maintenance window accordingly. Workaround trade-off: userspace Samba has slightly higher CPU overhead but eliminates kernel-level attack surface for this vulnerability class.