{"id":"CVE-2026-68142","state":"PUBLISHED","title":"geneve: require CAP_NET_ADMIN in the device netns for changelink","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngeneve: require CAP_NET_ADMIN in the device netns for changelink\n\nA tunnel changelink() operates on at most two netns, dev_net(dev) and\nthe sticky underlay netns geneve->net. They differ once the device is\ncreated in or moved to a netns other than the one the request runs in.\nThe rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev),\nso a caller privileged there but not in geneve->net can rewrite a geneve\ndevice whose underlay lives in geneve->net.\n\ngeneve_changelink() applies the new configuration against geneve->net:\ngeneve_link_config() and the geneve_quiesce()/geneve_unquiesce() pair\nreopen the underlay sockets in that netns (geneve_sock_add() uses\ngeneve->net), so the same reasoning as the tunnel changelink series\napplies here.\n\nGate geneve_changelink() with rtnl_dev_link_net_capable(), at the top of\nthe op before any attribute is parsed, matching ipgre_changelink() and\nthe rest of the \"require CAP_NET_ADMIN in the device netns for\nchangelink\" series.\n\nFound by 0sec automated security-research tooling (https://0sec.ai).","publishedAt":"2026-08-10T11:59:06.048Z","updatedAt":"2026-10-19T20:58:53.417Z","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":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"a5522963c57f12df5f9db804ebfc472b58eef0ae","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"278c6a31ee27c931c722202c8c06cc3253923254","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"11a7d989d00160481a273eb4f7f05f64b5a6ffdf","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"2abdacc927c92fa6a9cc8341e8c9b88dcb561553","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"9de5518fc1fab583526a8f66b8e505c4864dc60a","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"f8c498585d2a08aa623748353c3e61467b7e9fd2","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"95f45e20f1b2cec13823f0f68060ab4b2261b2c1","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/geneve.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.14","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","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":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","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":["drivers/net/geneve.c"]}],"references":["https://git.kernel.org/stable/c/a5522963c57f12df5f9db804ebfc472b58eef0ae","https://git.kernel.org/stable/c/278c6a31ee27c931c722202c8c06cc3253923254","https://git.kernel.org/stable/c/11a7d989d00160481a273eb4f7f05f64b5a6ffdf","https://git.kernel.org/stable/c/2abdacc927c92fa6a9cc8341e8c9b88dcb561553","https://git.kernel.org/stable/c/9de5518fc1fab583526a8f66b8e505c4864dc60a","https://git.kernel.org/stable/c/f8c498585d2a08aa623748353c3e61467b7e9fd2","https://git.kernel.org/stable/c/95f45e20f1b2cec13823f0f68060ab4b2261b2c1","https://git.kernel.org/stable/c/8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01"],"weaknesses":["CWE-862"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68142.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68142","state":"PUBLISHED","datePublished":"2026-08-10T11:59:06.048Z","dateUpdated":"2026-10-19T20:58:53.417Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.370Z"},"containers":{"cna":{"title":"geneve: 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\ngeneve: require CAP_NET_ADMIN in the device netns for changelink\n\nA tunnel changelink() operates on at most two netns, dev_net(dev) and\nthe sticky underlay netns geneve->net. They differ once the device is\ncreated in or moved to a netns other than the one the request runs in.\nThe rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev),\nso a caller privileged there but not in geneve->net can rewrite a geneve\ndevice whose underlay lives in geneve->net.\n\ngeneve_changelink() applies the new configuration against geneve->net:\ngeneve_link_config() and the geneve_quiesce()/geneve_unquiesce() pair\nreopen the underlay sockets in that netns (geneve_sock_add() uses\ngeneve->net), so the same reasoning as the tunnel changelink series\napplies here.\n\nGate geneve_changelink() with rtnl_dev_link_net_capable(), at the top of\nthe op before any attribute is parsed, matching ipgre_changelink() and\nthe rest of the \"require CAP_NET_ADMIN in the device netns for\nchangelink\" series.\n\nFound by 0sec automated security-research tooling (https://0sec.ai)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"a5522963c57f12df5f9db804ebfc472b58eef0ae","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"278c6a31ee27c931c722202c8c06cc3253923254","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"11a7d989d00160481a273eb4f7f05f64b5a6ffdf","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"2abdacc927c92fa6a9cc8341e8c9b88dcb561553","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"9de5518fc1fab583526a8f66b8e505c4864dc60a","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"f8c498585d2a08aa623748353c3e61467b7e9fd2","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"95f45e20f1b2cec13823f0f68060ab4b2261b2c1","versionType":"git"},{"version":"5b861f6baa3a22a48d7a4ad0ce38a223d36c978a","status":"affected","lessThan":"8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/geneve.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.14","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","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":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","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":["drivers/net/geneve.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a5522963c57f12df5f9db804ebfc472b58eef0ae"},{"url":"https://git.kernel.org/stable/c/278c6a31ee27c931c722202c8c06cc3253923254"},{"url":"https://git.kernel.org/stable/c/11a7d989d00160481a273eb4f7f05f64b5a6ffdf"},{"url":"https://git.kernel.org/stable/c/2abdacc927c92fa6a9cc8341e8c9b88dcb561553"},{"url":"https://git.kernel.org/stable/c/9de5518fc1fab583526a8f66b8e505c4864dc60a"},{"url":"https://git.kernel.org/stable/c/f8c498585d2a08aa623748353c3e61467b7e9fd2"},{"url":"https://git.kernel.org/stable/c/95f45e20f1b2cec13823f0f68060ab4b2261b2c1"},{"url":"https://git.kernel.org/stable/c/8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01"}],"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 issuing RTM_NEWLINK changelink over a local rtnetlink socket; geneve_changelink is only reachable from the rtnl configuration path, not from received GENEVE/UDP network packets.\nAC:L - Once a geneve device exists with geneve->net differing from dev_net(dev) (via IFLA_NET_NS_FD migration or IFLA_LINK_NETNSID newlink), 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 in dev_net(dev), obtainable by an unprivileged local user inside a user+network namespace via unshare --user --map-root-user --net; no CAP_NET_ADMIN in the sticky underlay netns geneve->net is needed.\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 - geneve_changelink applies geneve_link_config() and geneve_quiesce()/geneve_unquiesce() (reopening underlay sockets via geneve_sock_add() in geneve->net) while authorization is checked only against dev_net(dev), crossing into another tenant's or the host's network namespace.\nC:H - An attacker can set IFLA_GENEVE_REMOTE/REMOTE6 to redirect encapsulated overlay traffic to an attacker-controlled endpoint and read tunneled payloads from the victim underlay netns.\nI:H - Unauthorized changelink mutates live tunnel remote endpoint, TTL/TOS/DF/label, and MTU in geneve->net, enabling redirection and injection of overlay traffic without authorization in that namespace.\nA:H - geneve_quiesce() drops in-flight tunnel traffic and rewriting the remote endpoint or MTU breaks production GENEVE overlays (Kubernetes/OVN/cloud SDN), causing sustained loss of connectivity for dependent services."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:30:02.355Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68142","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:44:41.067135Z"}}}],"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":"2026-10-19T20:58:53.417Z"}}]}}}