{"id":"CVE-2026-72136","state":"PUBLISHED","title":"xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink\n\nxfrmi_changelink() operates on at most two netns, dev_net(dev) and the\ninterface link netns xi->net. They differ once the device is created in\nor moved to a netns other than the one the request runs in. The rtnl\nchangelink path checks CAP_NET_ADMIN only against dev_net(dev), so a\ncaller privileged there but not in xi->net can rewrite an interface that\nlives in xi->net.\n\nGate xfrmi_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed.","publishedAt":"2026-08-15T05:53:11.072Z","updatedAt":"2026-10-16T18:44:58.796Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"04c1aa57d08471b1953bf27c84ac9b3d78d71831","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"bdfd1c21d90e628a58a9de79e024cdfcbedfa15c","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"80ec68bba11f7f387c0e4099c2d7b2c84943eb99","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"e9c90756f10da334fb31552e52c61f1dba69f491","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"37b61946d278c7deb0d40ba8f2b6fc0478d61dab","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"8ca2a19a987a7d1cb4c916ed9723a1c6993b4276","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"3ba2b2ef7d6a63b190f15cfc2b4ba0fba59928ea","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"095515d89b19b6cc19dfcdc846f97403ed1ebce3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_interface_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_interface_core.c"]}],"references":["https://git.kernel.org/stable/c/04c1aa57d08471b1953bf27c84ac9b3d78d71831","https://git.kernel.org/stable/c/bdfd1c21d90e628a58a9de79e024cdfcbedfa15c","https://git.kernel.org/stable/c/80ec68bba11f7f387c0e4099c2d7b2c84943eb99","https://git.kernel.org/stable/c/e9c90756f10da334fb31552e52c61f1dba69f491","https://git.kernel.org/stable/c/37b61946d278c7deb0d40ba8f2b6fc0478d61dab","https://git.kernel.org/stable/c/8ca2a19a987a7d1cb4c916ed9723a1c6993b4276","https://git.kernel.org/stable/c/3ba2b2ef7d6a63b190f15cfc2b4ba0fba59928ea","https://git.kernel.org/stable/c/095515d89b19b6cc19dfcdc846f97403ed1ebce3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72136.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72136","state":"PUBLISHED","datePublished":"2026-08-15T05:53:11.072Z","dateUpdated":"2026-10-16T18:44:58.796Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.908Z"},"containers":{"cna":{"title":"xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink\n\nxfrmi_changelink() operates on at most two netns, dev_net(dev) and the\ninterface link netns xi->net. They differ once the device is created in\nor moved to a netns other than the one the request runs in. The rtnl\nchangelink path checks CAP_NET_ADMIN only against dev_net(dev), so a\ncaller privileged there but not in xi->net can rewrite an interface that\nlives in xi->net.\n\nGate xfrmi_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"04c1aa57d08471b1953bf27c84ac9b3d78d71831","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"bdfd1c21d90e628a58a9de79e024cdfcbedfa15c","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"80ec68bba11f7f387c0e4099c2d7b2c84943eb99","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"e9c90756f10da334fb31552e52c61f1dba69f491","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"37b61946d278c7deb0d40ba8f2b6fc0478d61dab","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"8ca2a19a987a7d1cb4c916ed9723a1c6993b4276","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"3ba2b2ef7d6a63b190f15cfc2b4ba0fba59928ea","versionType":"git"},{"version":"f203b76d78092faf248db3f851840fbecf80b40e","status":"affected","lessThan":"095515d89b19b6cc19dfcdc846f97403ed1ebce3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_interface_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_interface_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/04c1aa57d08471b1953bf27c84ac9b3d78d71831"},{"url":"https://git.kernel.org/stable/c/bdfd1c21d90e628a58a9de79e024cdfcbedfa15c"},{"url":"https://git.kernel.org/stable/c/80ec68bba11f7f387c0e4099c2d7b2c84943eb99"},{"url":"https://git.kernel.org/stable/c/e9c90756f10da334fb31552e52c61f1dba69f491"},{"url":"https://git.kernel.org/stable/c/37b61946d278c7deb0d40ba8f2b6fc0478d61dab"},{"url":"https://git.kernel.org/stable/c/8ca2a19a987a7d1cb4c916ed9723a1c6993b4276"},{"url":"https://git.kernel.org/stable/c/3ba2b2ef7d6a63b190f15cfc2b4ba0fba59928ea"},{"url":"https://git.kernel.org/stable/c/095515d89b19b6cc19dfcdc846f97403ed1ebce3"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires a local RTM_NEWLINK changelink over an rtnetlink/netlink socket (rtnl_newlink → rtnl_changelink → xfrmi_changelink); this is a netlink configuration path, not remote packet handling, matching kernel Local guidance.\nAC:L - Once a cross-namespace xfrmi exists (dev_net(dev) ≠ xi->net via IFLA_LINK_NETNSID creation or netns migration), bypassing the missing check is one deterministic changelink with attacker-chosen IFLA_XFRM_IF_ID; no race, timing, or layout dependency.\nPR:L - rtnl_link_get_net_capable() only requires CAP_NET_ADMIN in dev_net(dev), obtainable by an unprivileged user via user+network namespaces (unshare -Urn / map-root-user); CAP_NET_ADMIN in the sticky link netns xi->net is not required.\nUI:N - The attack is fully programmatic from the attacker's own process through netlink; no victim action such as mounting a filesystem, opening a file, or clicking is required.\nS:C - Privilege is checked against dev_net(dev) while xfrmi_changelink/xfrmi_update mutate live xfrm interface state in xi->net (hash unlink/relink, if_id binding), crossing from the attacker's net/user namespace into another tenant's or the host network namespace.\nC:H - Changing IFLA_XFRM_IF_ID in xi->net retargets xfrmi_lookup/xfrm_lookup_with_ifid so host IPsec SAs can deliver decrypted VPN cleartext to the attacker-controlled netdev in dev_net(dev), exposing confidential tunneled traffic.\nI:H - Unauthorized changelink rewrites live xfrm interface parameters and xi->net registration, enabling redirection or injection of IPsec encapsulation/decapsulation paths on Internet-facing VPN gateways and cloud IPsec endpoints.\nA:H - xfrmi_update() runs synchronize_net() and netdev_state_change(); 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