{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72051", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.902Z", "datePublished": "2026-08-15T05:52:08.445Z", "dateUpdated": "2026-08-23T12:46:34.252Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:46:34.252Z" }, "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." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_tunnel.c" ], "versions": [ { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "2d53ee7daabe733deb81f51d2cc90188f8ad59a1", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "82e53e7281c71e174f9f5877c566a623c637b406", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "5252db8fb604321133138c7069d6fc3fcd89cdee", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "2636d061bc237a2446a146e42dcc6563acfa7432", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "7f68f7928484f463a5bc0d50e6fdd8d16f55a5aa", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "234cd54fc500f69db43e37de38603da617fbbeea", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "d4bcc202a3530c856e1cb183384bc9cc8fddab22", "status": "affected", "versionType": "git" }, { "version": "0bd8762824e73a3cce7b7560a97463301764b616", "lessThan": "2496fa0b7d180b3ad356b514e7ff93bb14e6140a", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_tunnel.c" ], "versions": [ { "version": "3.12", "status": "affected" }, { "version": "0", "lessThan": "3.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "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" } ] } ] } ], "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" } ], "title": "net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink", "x_generator": { "engine": "bippy-1.2.0" } } } }