CVE-2026-68432
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel's VXLAN driver, there is a missing CAP_NET_ADMIN requirement in the device network namespace during changelink operations. A caller privileged in the device namespace but not in the underlay namespace can modify VXLAN tunnel configuration, potentially leading to unauthorized changes.
Risk Assessment
The vulnerability may allow an unauthorized user to modify VXLAN tunnel configurations, potentially leading to traffic interception or network integrity compromise.
Recommendation
Apply the Linux kernel update containing the fix that requires CAP_NET_ADMIN in the device namespace for changelink operations.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: vxlan: 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 vxlan->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 vxlan->net can rewrite a vxlan device whose underlay lives in vxlan->net. vxlan_changelink() validates and applies the new configuration against vxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the underlay socket in that netns, so the same reasoning as the tunnel changelink series applies here. Gate vxlan_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).