CVE-2026-68142
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
In the Linux kernel's geneve module, the function geneve_changelink() does not check for CAP_NET_ADMIN in the device's network namespace (dev_net(dev)), allowing a caller with privileges only in one namespace to modify a geneve device whose underlay operates in another namespace.
Risk Assessment
The risk includes the possibility of unauthorized modification of network tunnel configurations, which could lead to traffic interception, network disruption, or privilege escalation.
Recommendation
It is recommended to apply the kernel patch that adds rtnl_dev_link_net_capable() at the top of geneve_changelink(), and to update systems.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: geneve: require CAP_NET_ADMIN in the device netns for changelink A tunnel changelink() operates on at most two netns, dev_net(dev) and the sticky underlay netns geneve->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 geneve->net can rewrite a geneve device whose underlay lives in geneve->net. geneve_changelink() applies the new configuration against geneve->net: geneve_link_config() and the geneve_quiesce()/geneve_unquiesce() pair reopen the underlay sockets in that netns (geneve_sock_add() uses geneve->net), so the same reasoning as the tunnel changelink series applies here. Gate geneve_changelink() with rtnl_dev_link_net_capable(), at the top of the op before any attribute is parsed, matching ipgre_changelink() and the rest of the "require CAP_NET_ADMIN in the device netns for changelink" series. Found by 0sec automated security-research tooling (https://0sec.ai).