{"id":"CVE-2026-68432","state":"PUBLISHED","title":"vxlan: require CAP_NET_ADMIN in the device netns for changelink","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: 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 vxlan->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 vxlan->net can rewrite a vxlan\ndevice whose underlay lives in vxlan->net.\n\nvxlan_changelink() validates and applies the new configuration against\nvxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the\nunderlay socket in that netns, so the same reasoning as the tunnel\nchangelink series applies here.\n\nGate vxlan_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":"2026-08-12T00:07:18.806Z","updatedAt":"2026-10-19T21:09:10.150Z","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":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"b95a8743e58f7efed5ddc4cb73829b66f17feab0","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"7465ade989ba84adc2bfa58bad3ca25d249f0f7a","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"0aa580a8bbbed2507b4582a1f0ef581d480d06ed","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"b3793d7dccb192ffff29894d11824db6251acdd5","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"32d10c46bfde3e9b274e9e1bd6399d0ebea8f60f","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"730c7e5fea7f06e0cdf21c547222ec93234fd1d6","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"e8ad0d311e225939a9a6c745d6cc384c7364ec87","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","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/vxlan/vxlan_core.c"]}],"references":["https://git.kernel.org/stable/c/b95a8743e58f7efed5ddc4cb73829b66f17feab0","https://git.kernel.org/stable/c/7465ade989ba84adc2bfa58bad3ca25d249f0f7a","https://git.kernel.org/stable/c/0aa580a8bbbed2507b4582a1f0ef581d480d06ed","https://git.kernel.org/stable/c/b3793d7dccb192ffff29894d11824db6251acdd5","https://git.kernel.org/stable/c/32d10c46bfde3e9b274e9e1bd6399d0ebea8f60f","https://git.kernel.org/stable/c/730c7e5fea7f06e0cdf21c547222ec93234fd1d6","https://git.kernel.org/stable/c/e8ad0d311e225939a9a6c745d6cc384c7364ec87","https://git.kernel.org/stable/c/3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68432.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68432","state":"PUBLISHED","datePublished":"2026-08-12T00:07:18.806Z","dateUpdated":"2026-10-19T21:09:10.150Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.393Z"},"containers":{"cna":{"title":"vxlan: 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\nvxlan: 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 vxlan->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 vxlan->net can rewrite a vxlan\ndevice whose underlay lives in vxlan->net.\n\nvxlan_changelink() validates and applies the new configuration against\nvxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the\nunderlay socket in that netns, so the same reasoning as the tunnel\nchangelink series applies here.\n\nGate vxlan_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":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"b95a8743e58f7efed5ddc4cb73829b66f17feab0","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"7465ade989ba84adc2bfa58bad3ca25d249f0f7a","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"0aa580a8bbbed2507b4582a1f0ef581d480d06ed","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"b3793d7dccb192ffff29894d11824db6251acdd5","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"32d10c46bfde3e9b274e9e1bd6399d0ebea8f60f","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"730c7e5fea7f06e0cdf21c547222ec93234fd1d6","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"e8ad0d311e225939a9a6c745d6cc384c7364ec87","versionType":"git"},{"version":"8bcdc4f3a20be949df54b67e5ae2734daabb5792","status":"affected","lessThan":"3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","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/vxlan/vxlan_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b95a8743e58f7efed5ddc4cb73829b66f17feab0"},{"url":"https://git.kernel.org/stable/c/7465ade989ba84adc2bfa58bad3ca25d249f0f7a"},{"url":"https://git.kernel.org/stable/c/0aa580a8bbbed2507b4582a1f0ef581d480d06ed"},{"url":"https://git.kernel.org/stable/c/b3793d7dccb192ffff29894d11824db6251acdd5"},{"url":"https://git.kernel.org/stable/c/32d10c46bfde3e9b274e9e1bd6399d0ebea8f60f"},{"url":"https://git.kernel.org/stable/c/730c7e5fea7f06e0cdf21c547222ec93234fd1d6"},{"url":"https://git.kernel.org/stable/c/e8ad0d311e225939a9a6c745d6cc384c7364ec87"},{"url":"https://git.kernel.org/stable/c/3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e"}],"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 an RTM_NEWLINK changelink request over an rtnetlink socket on the local system, matching the kernel guidance that netlink configuration paths are Local.\nAC:L - Once a cross-namespace vxlan device is present in the caller's netns, the missing check is bypassed by a single deterministic netlink changelink call with no race, timing, or memory-layout dependency.\nPR:L - The rtnl entry path only requires CAP_NET_ADMIN in dev_net(dev), which an unprivileged user obtains inside a user namespace via unshare --user --map-root-user --net; no privilege in the underlay netns vxlan->net is needed.\nUI:N - The attack is fully programmatic through netlink from the attacker's own process; no victim action such as mounting, opening a file, or clicking is required.\nS:C - Authorization is evaluated against dev_net(dev) while the configuration is validated and applied against vxlan->net, so the impact crosses from the attacker's net/user namespace into another tenant's or the host's network namespace.\nC:H - The attacker can rewrite IFLA_VXLAN_GROUP/LOCAL and the underlay IFLA_VXLAN_LINK so encapsulated overlay traffic in the victim netns is sent to an attacker-controlled endpoint, exposing tunneled payloads.\nI:H - Unauthorized changelink mutates live tunnel state in the victim underlay netns (remote/local addresses, lower device, TOS/TTL/label, learning and proxy/RSC flags, default-remote FDB entries), enabling redirection and injection of overlay traffic.\nA:H - Rewriting the remote group, source address, or lower device tears down and re-establishes multicast group membership and forwarding state, causing sustained loss of connectivity for every service riding the affected VXLAN overlay."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:35:30.743Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68432","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:48:52.480523Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","type":"CWE","description":"CWE-863 Incorrect Authorization"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:09:10.150Z"}}]}}}