CVE-2026-52909: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ip6_vti: set netns_immutable on the fallback device. john1988 and Noam Rathaus reported that vti6_init_net() does not set the netns_immutable flag on the per-netns fallback tunnel device (ip6_vti0). Other similar tunnel drivers (like ip6_tunnel, sit, ip6_gre, and ip_tunnel) correctly set this flag during their fallback device initialization to prevent them from being moved to another network namespace.

Affected products

• Linux Linux Kernel: from 3.15, before 5.10.260 (fixed in 5.10.260); from 5.11, before 5.15.211 (fixed in 5.15.211); from 5.16, before 6.1.177 (fixed in 6.1.177); from 6.2, before 6.6.144 (fixed in 6.6.144); from 6.7, before 6.12.95 (fixed in 6.12.95); from 6.13, before 6.18.36 (fixed in 6.18.36); …

Published 2026-06-19. Last modified 2026-07-08.