{"id":"CVE-2026-72051","state":"PUBLISHED","title":"net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink\n\nip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the\ntunnel link netns t->net. They differ once the device is created in or\nmoved 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 t->net can rewrite a tunnel that\nlives in t->net.\n\nGate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed.","publishedAt":"2026-08-15T05:52:08.445Z","updatedAt":"2026-10-19T21:19:24.769Z","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":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2d53ee7daabe733deb81f51d2cc90188f8ad59a1","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"82e53e7281c71e174f9f5877c566a623c637b406","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"5252db8fb604321133138c7069d6fc3fcd89cdee","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2636d061bc237a2446a146e42dcc6563acfa7432","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"234cd54fc500f69db43e37de38603da617fbbeea","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"d4bcc202a3530c856e1cb183384bc9cc8fddab22","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2496fa0b7d180b3ad356b514e7ff93bb14e6140a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_tunnel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.12","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","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/ipv6/ip6_tunnel.c"]}],"references":["https://git.kernel.org/stable/c/2d53ee7daabe733deb81f51d2cc90188f8ad59a1","https://git.kernel.org/stable/c/82e53e7281c71e174f9f5877c566a623c637b406","https://git.kernel.org/stable/c/5252db8fb604321133138c7069d6fc3fcd89cdee","https://git.kernel.org/stable/c/2636d061bc237a2446a146e42dcc6563acfa7432","https://git.kernel.org/stable/c/7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa","https://git.kernel.org/stable/c/234cd54fc500f69db43e37de38603da617fbbeea","https://git.kernel.org/stable/c/d4bcc202a3530c856e1cb183384bc9cc8fddab22","https://git.kernel.org/stable/c/2496fa0b7d180b3ad356b514e7ff93bb14e6140a"],"weaknesses":["CWE-862"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72051.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72051","state":"PUBLISHED","datePublished":"2026-08-15T05:52:08.445Z","dateUpdated":"2026-10-19T21:19:24.769Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.902Z"},"containers":{"cna":{"title":"net: ip6_tunnel: 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\nnet: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink\n\nip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the\ntunnel link netns t->net. They differ once the device is created in or\nmoved 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 t->net can rewrite a tunnel that\nlives in t->net.\n\nGate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top,\nbefore any attribute is parsed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2d53ee7daabe733deb81f51d2cc90188f8ad59a1","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"82e53e7281c71e174f9f5877c566a623c637b406","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"5252db8fb604321133138c7069d6fc3fcd89cdee","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2636d061bc237a2446a146e42dcc6563acfa7432","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"234cd54fc500f69db43e37de38603da617fbbeea","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"d4bcc202a3530c856e1cb183384bc9cc8fddab22","versionType":"git"},{"version":"0bd8762824e73a3cce7b7560a97463301764b616","status":"affected","lessThan":"2496fa0b7d180b3ad356b514e7ff93bb14e6140a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_tunnel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.12","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","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/ipv6/ip6_tunnel.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2d53ee7daabe733deb81f51d2cc90188f8ad59a1"},{"url":"https://git.kernel.org/stable/c/82e53e7281c71e174f9f5877c566a623c637b406"},{"url":"https://git.kernel.org/stable/c/5252db8fb604321133138c7069d6fc3fcd89cdee"},{"url":"https://git.kernel.org/stable/c/2636d061bc237a2446a146e42dcc6563acfa7432"},{"url":"https://git.kernel.org/stable/c/7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa"},{"url":"https://git.kernel.org/stable/c/234cd54fc500f69db43e37de38603da617fbbeea"},{"url":"https://git.kernel.org/stable/c/d4bcc202a3530c856e1cb183384bc9cc8fddab22"},{"url":"https://git.kernel.org/stable/c/2496fa0b7d180b3ad356b514e7ff93bb14e6140a"}],"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 RTM_NEWLINK changelink over a local rtnetlink socket; ip6_tnl_changelink is only reachable from rtnl configuration, not from received IPv6 packets processed by ip6_tnl_rcv.\nAC:L - Once an ip6tnl device exists with t->net differing from dev_net(dev) (IFLA_LINK_NETNSID newlink or IFLA_NET_NS_FD migration), a single deterministic netlink changelink bypasses the missing check with no race or memory-layout dependency.\nPR:L - The rtnl entry path requires CAP_NET_ADMIN only in dev_net(dev), obtainable by an unprivileged local user via unshare --user --map-root-user --net; no CAP_NET_ADMIN in the sticky link netns t->net is required.\nUI:N - The attack is fully programmatic through netlink from the attacker's own process; no victim action such as mounting a filesystem, opening a file, or clicking is required.\nS:C - Authorization is checked against dev_net(dev) while ip6_tnl_changelink mutates tunnel state in t->net via ip6_tnl_update, crossing from the attacker's net/user namespace into another tenant's or the host's network namespace.\nC:H - An attacker can rewrite IFLA_IPTUN_LOCAL/REMOTE, link, fwmark, and encap parameters to redirect IPv6/IPv4-over-IPv6 tunnel traffic to an attacker-controlled endpoint and read all tunneled payloads in the victim link netns.\nI:H - Unauthorized changelink updates live tunnel endpoints, underlay link, encap ports, and flowinfo/fwmark in t->net, enabling redirection and injection of traffic carried over the ip6tnl tunnel.\nA:H - Rewriting tunnel remote/local addresses, underlay device, or encap parameters breaks cross-netns IPv6 tunnel connectivity, causing sustained loss of service for every workload depending on the affected ip6tnl tunnel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-23T12:46:34.252Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"5.10.266"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"5.15.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.1.184"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72051","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:50:49.406675Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-862","lang":"en","type":"CWE","description":"CWE-862 Missing Authorization"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:19:24.769Z"}}]}}}