{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68432", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.393Z", "datePublished": "2026-08-12T00:07:18.806Z", "dateUpdated": "2026-08-19T16:35:30.743Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:35:30.743Z" }, "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)." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/vxlan/vxlan_core.c" ], "versions": [ { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "b95a8743e58f7efed5ddc4cb73829b66f17feab0", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "7465ade989ba84adc2bfa58bad3ca25d249f0f7a", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "0aa580a8bbbed2507b4582a1f0ef581d480d06ed", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "b3793d7dccb192ffff29894d11824db6251acdd5", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "32d10c46bfde3e9b274e9e1bd6399d0ebea8f60f", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "730c7e5fea7f06e0cdf21c547222ec93234fd1d6", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "e8ad0d311e225939a9a6c745d6cc384c7364ec87", "status": "affected", "versionType": "git" }, { "version": "8bcdc4f3a20be949df54b67e5ae2734daabb5792", "lessThan": "3a61bd9637f3d929aa846e4eb3d98b48c26fcb0e", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/vxlan/vxlan_core.c" ], "versions": [ { "version": "4.11", "status": "affected" }, { "version": "0", "lessThan": "4.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "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": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "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" } ] } ] } ], "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" } ], "title": "vxlan: require CAP_NET_ADMIN in the device netns for changelink", "x_generator": { "engine": "bippy-1.2.0" } } } }