Linux Kernel EUVD-2026-45775

The primary fix is to update the Linux kernel to a patched stable release: 5.10.259 or later on the 5.10 branch, 5.15.210 or later on the 5.15 branch, 6.1.176 or later on the 6.1 branch, 6.6.143 or later on the 6.6 branch, 6.12.93 or later on the 6.12 branch, 6.18.34 or later on the 6.18 branch, 7.0.11 or later on the 7.0 branch, or 7.1+ on current mainline. Upstream patch commits are available at https://git.kernel.org/stable/c/1f467d9a095211d3f77e8ff1bee90e73ffe01c64 and https://git.kernel.org/stable/c/9a02c8fc963ddeecb5d8788be0740c1869fc54b7 among others. Ubuntu users should apply USN-8593-1 via standard package manager updates. For systems that cannot be patched immediately, unloading the batman-adv module (rmmod batman_adv) eliminates exposure entirely - the trade-off is complete loss of mesh networking functionality for the duration. Alternatively, restricting unprivileged access to network namespaces via sysctl net.core.unprivileged_restricted=1 (where supported) or removing CAP_NET_ADMIN from untrusted processes provides partial mitigation without disabling batman-adv globally, though this does not eliminate the vulnerability for users who retain network capability.