What’s Vulnerable › Vulnerabilities

CVE-2026-52909: ip6_vti: set netns_immutable on the fallback device.

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-19 · updated 2026-10-19
• Weakness: CWE-863

Description

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 kernel: from 3.15 before 5.10.260; from 5.11 before 5.15.211; from 5.16 before 6.1.177; from 6.2 before 6.6.144; from 6.7 before 6.12.95; from 6.13 before 6.18.36 — fixed in 5.10.260, 5.15.211, 6.1.177, 6.12.95, 6.18.36, 6.6.144

How to fix

Upgrade to a fixed version: Linux kernel 5.10.260, 5.15.211, 6.1.177, 6.12.95. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/12acc977838c943636fb01e2f3087d2e4cc3b7cc
• https://git.kernel.org/stable/c/12c65e2c7fef507551bd7b52123598a761662c01
• https://git.kernel.org/stable/c/7f28e3948c59481f8db9c9638e204258d26b4e41
• https://git.kernel.org/stable/c/c5dbd669db5a426b3025512322e1bf2cdbe14305
• https://git.kernel.org/stable/c/d289d5307762d1838aaece22c6b6fcad9e8865f9
• https://git.kernel.org/stable/c/dcdce3bc9f08026ff3739ee7339e1bef526fc5f3
• https://git.kernel.org/stable/c/ecf8904067dcba0dad86ece80874841e60317885
• https://git.kernel.org/stable/c/f4b6b4af7ef0661ac153c6f7eb1030aa8482c1a3
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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