net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink

Summary

In the Linux kernel, the following vulnerability has been resolved: net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink ip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed.

Timeline

1. Aug 15, 2026, 5:52 AM UTCCVE published
2. Oct 16, 2026, 3:50 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 19, 2026, 9:19 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 2d53ee7daabe733deb81f51d2cc90188f8ad59a1; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 82e53e7281c71e174f9f5877c566a623c637b406; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 5252db8fb604321133138c7069d6fc3fcd89cdee; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 2636d061bc237a2446a146e42dcc6563acfa7432; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 234cd54fc500f69db43e37de38603da617fbbeea; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in d4bcc202a3530c856e1cb183384bc9cc8fddab22; From 0bd8762824e73a3cce7b7560a97463301764b616 · fixed in 2496fa0b7d180b3ad356b514e7ff93bb14e6140a

• Linux Linux

  3.12

• KernelLinux

  From 3.12.0 · fixed in 5.10.266; From 5.11.0 · fixed in 5.15.217; From 5.16.0 · fixed in 6.1.184; From 6.2.0 · fixed in 6.6.148; From 6.7.0 · fixed in 6.12.101; From 6.13.0 · fixed in 6.18.40; From 6.19.0 · fixed in 7.1.5

References 8