CVE-2026-63921

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-63921", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.020Z", "datePublished": "2026-07-19T14:55:23.539Z", "dateUpdated": "2026-10-19T20:17:56.432Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:37:15.900Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().\n\nAfter patch 1/2 in this series, vti6_update() unlinks and relinks\nthe tunnel through t->net. vti6_siocdevprivate() still uses\ndev_net(dev) for the collision lookup. For a tunnel moved through\nIFLA_NET_NS_FD, dev_net(dev) is the new netns, not t->net.\n\nSIOCCHGTUNNEL on a migrated tunnel then runs:\n\n net = dev_net(dev) /* migrated netns */\n t = vti6_locate(net, &p1, false) /* misses target in t->net */\n ...\n t = netdev_priv(dev)\n vti6_update(t, &p1, false) /* mutates t->net's hash */\n\nA caller in the migrated netns picks params that match a tunnel\nin the creation netns. The lookup in dev_net(dev) finds nothing.\nvti6_update() prepends the migrated tunnel at the head of the\ncreation netns hash bucket for those params. Later lookups in\nthe creation netns resolve to the migrated device. xfrm receive\ndelivers the matched packets through a device the caller controls.\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net). Cross tenant scope on container hosts.\n\nSwitch the SIOCCHGTUNNEL path on a non fallback device to use\nt->net for the lookup. The lookup now matches the netns\nvti6_update() operates on.\n\nAlso add ns_capable(self->net->user_ns, CAP_NET_ADMIN) before\nthe lookup. The check at the top of the case is against\ndev_net(dev)->user_ns, which after migration is the attacker's\nnetns. A caller there can pick params absent from self->net,\nthe lookup returns NULL, t becomes self, and vti6_update()\ninserts the device into the creation netns hash. The new check\nrequires CAP_NET_ADMIN in the creation netns user_ns too.\n\nSIOCADDTUNNEL and SIOCCHGTUNNEL on the fallback device keep\ndev_net(dev), which equals init_net there."}], "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 a local ioctl(SIOCCHGTUNNEL) on a migrated vti6 netdev via socket/dev_ioctl; the bug is in vti6_siocdevprivate(), not in remote packet reception.\nAC:L - The attacker fully controls namespace creation, tunnel migration (IFLA_NET_NS_FD), and ioctl parameters to collide with a victim tunnel; the commit documents a deterministic, reproducible sequence with no uncontrollable race.\nPR:L - Only CAP_NET_ADMIN in the migrated (attacker) network namespace is required, obtainable via unprivileged user namespaces (unshare --user --map-root-user --net); the missing check against the creation namespace's user_ns is the core flaw.\nUI:N - No victim interaction is needed; the attacker performs all setup steps (create/migrate tunnel, issue SIOCCHGTUNNEL) autonomously.\nS:C - The attack hijacks IPsec/XFRM traffic destined for tunnels in a different tenant's network namespace on container hosts, crossing container/tenant security boundaries rather than staying within the attacker's own scope.\nC:H - After hash poisoning, xfrm receive delivers matched/decapsulated packets to the attacker-controlled netdev, enabling interception of victim VPN/IPsec traffic including potentially sensitive plaintext after decryption.\nI:H - The attacker gains control over which netdev receives victim tunnel traffic and can read, drop, or forward/modify decapsulated packets, constituting unauthorized manipulation of another tenant's network data path.\nA:H - Hijacking the creation-namespace hash bucket causes the legitimate victim tunnel to stop receiving matched traffic, producing denial of service to the victim's IPsec connectivity."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv6/ip6_vti.c"], "versions": [{"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "94ff740a7f9ef5c010784a325dca00cbf228f941", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "df42ac708acc3399bbb6dc5ca16e0540adda7bbf", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "44d2ff7d2178503b93151140a45dfa2ad49c9906", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "1acfb7d9c6fc7e209ed7789392697e97e03edd33", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "d2236348414bdd6558385f35aa7fdc9bf5634011", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "853f6ea482dfcd3404bbef458ab4d68364eed838", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "596f6354c96a891e58c04a09cbfb7b0d1ec00dab", "status": "affected", "versionType": "git"}, {"version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "8b484efd5cb4eeef9021a661e198edc5349dacf6", "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_vti.c"], "versions": [{"version": "3.15", "status": "affected"}, {"version": "0", "lessThan": "3.15", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "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": "3.15", "versionEndExcluding": "5.10.259"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "5.15.210"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.1.176"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.6.143"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.12.93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.18.35"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "7.0.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/94ff740a7f9ef5c010784a325dca00cbf228f941"}, {"url": "https://git.kernel.org/stable/c/df42ac708acc3399bbb6dc5ca16e0540adda7bbf"}, {"url": "https://git.kernel.org/stable/c/44d2ff7d2178503b93151140a45dfa2ad49c9906"}, {"url": "https://git.kernel.org/stable/c/1acfb7d9c6fc7e209ed7789392697e97e03edd33"}, {"url": "https://git.kernel.org/stable/c/d2236348414bdd6558385f35aa7fdc9bf5634011"}, {"url": "https://git.kernel.org/stable/c/853f6ea482dfcd3404bbef458ab4d68364eed838"}, {"url": "https://git.kernel.org/stable/c/596f6354c96a891e58c04a09cbfb7b0d1ec00dab"}, {"url": "https://git.kernel.org/stable/c/8b484efd5cb4eeef9021a661e198edc5349dacf6"}], "title": "ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-63921", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:33:25.874966Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-862", "description": "CWE-862 Missing Authorization"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:17:56.432Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-63921", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:33:25.874966Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-862", "description": "CWE-862 Missing Authorization"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:33:26.437Z"}}], "cna": {"title": "ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - Exploitation requires a local ioctl(SIOCCHGTUNNEL) on a migrated vti6 netdev via socket/dev_ioctl; the bug is in vti6_siocdevprivate(), not in remote packet reception.\nAC:L - The attacker fully controls namespace creation, tunnel migration (IFLA_NET_NS_FD), and ioctl parameters to collide with a victim tunnel; the commit documents a deterministic, reproducible sequence with no uncontrollable race.\nPR:L - Only CAP_NET_ADMIN in the migrated (attacker) network namespace is required, obtainable via unprivileged user namespaces (unshare --user --map-root-user --net); the missing check against the creation namespace's user_ns is the core flaw.\nUI:N - No victim interaction is needed; the attacker performs all setup steps (create/migrate tunnel, issue SIOCCHGTUNNEL) autonomously.\nS:C - The attack hijacks IPsec/XFRM traffic destined for tunnels in a different tenant's network namespace on container hosts, crossing container/tenant security boundaries rather than staying within the attacker's own scope.\nC:H - After hash poisoning, xfrm receive delivers matched/decapsulated packets to the attacker-controlled netdev, enabling interception of victim VPN/IPsec traffic including potentially sensitive plaintext after decryption.\nI:H - The attacker gains control over which netdev receives victim tunnel traffic and can read, drop, or forward/modify decapsulated packets, constituting unauthorized manipulation of another tenant's network data path.\nA:H - Hijacking the creation-namespace hash bucket causes the legitimate victim tunnel to stop receiving matched traffic, producing denial of service to the victim's IPsec connectivity."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "94ff740a7f9ef5c010784a325dca00cbf228f941", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "df42ac708acc3399bbb6dc5ca16e0540adda7bbf", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "44d2ff7d2178503b93151140a45dfa2ad49c9906", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "1acfb7d9c6fc7e209ed7789392697e97e03edd33", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "d2236348414bdd6558385f35aa7fdc9bf5634011", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "853f6ea482dfcd3404bbef458ab4d68364eed838", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "596f6354c96a891e58c04a09cbfb7b0d1ec00dab", "versionType": "git"}, {"status": "affected", "version": "61220ab349485d911083d0b7990ccd3db6c63297", "lessThan": "8b484efd5cb4eeef9021a661e198edc5349dacf6", "versionType": "git"}], "programFiles": ["net/ipv6/ip6_vti.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "3.15"}, {"status": "unaffected", "version": "0", "lessThan": "3.15", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.259", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.210", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.176", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.143", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.93", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.35", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.12", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/ipv6/ip6_vti.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/94ff740a7f9ef5c010784a325dca00cbf228f941"}, {"url": "https://git.kernel.org/stable/c/df42ac708acc3399bbb6dc5ca16e0540adda7bbf"}, {"url": "https://git.kernel.org/stable/c/44d2ff7d2178503b93151140a45dfa2ad49c9906"}, {"url": "https://git.kernel.org/stable/c/1acfb7d9c6fc7e209ed7789392697e97e03edd33"}, {"url": "https://git.kernel.org/stable/c/d2236348414bdd6558385f35aa7fdc9bf5634011"}, {"url": "https://git.kernel.org/stable/c/853f6ea482dfcd3404bbef458ab4d68364eed838"}, {"url": "https://git.kernel.org/stable/c/596f6354c96a891e58c04a09cbfb7b0d1ec00dab"}, {"url": "https://git.kernel.org/stable/c/8b484efd5cb4eeef9021a661e198edc5349dacf6"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().\n\nAfter patch 1/2 in this series, vti6_update() unlinks and relinks\nthe tunnel through t->net. vti6_siocdevprivate() still uses\ndev_net(dev) for the collision lookup. For a tunnel moved through\nIFLA_NET_NS_FD, dev_net(dev) is the new netns, not t->net.\n\nSIOCCHGTUNNEL on a migrated tunnel then runs:\n\n net = dev_net(dev) /* migrated netns */\n t = vti6_locate(net, &p1, false) /* misses target in t->net */\n ...\n t = netdev_priv(dev)\n vti6_update(t, &p1, false) /* mutates t->net's hash */\n\nA caller in the migrated netns picks params that match a tunnel\nin the creation netns. The lookup in dev_net(dev) finds nothing.\nvti6_update() prepends the migrated tunnel at the head of the\ncreation netns hash bucket for those params. Later lookups in\nthe creation netns resolve to the migrated device. xfrm receive\ndelivers the matched packets through a device the caller controls.\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net). Cross tenant scope on container hosts.\n\nSwitch the SIOCCHGTUNNEL path on a non fallback device to use\nt->net for the lookup. The lookup now matches the netns\nvti6_update() operates on.\n\nAlso add ns_capable(self->net->user_ns, CAP_NET_ADMIN) before\nthe lookup. The check at the top of the case is against\ndev_net(dev)->user_ns, which after migration is the attacker's\nnetns. A caller there can pick params absent from self->net,\nthe lookup returns NULL, t becomes self, and vti6_update()\ninserts the device into the creation netns hash. The new check\nrequires CAP_NET_ADMIN in the creation netns user_ns too.\n\nSIOCADDTUNNEL and SIOCCHGTUNNEL on the fallback device keep\ndev_net(dev), which equals init_net there."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.259", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.210", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.176", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.143", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.93", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.35", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0.12", "versionStartIncluding": "3.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1", "versionStartIncluding": "3.15"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:37:15.900Z"}}}, "cveMetadata": {"cveId": "CVE-2026-63921", "state": "PUBLISHED", "dateUpdated": "2026-10-19T20:17:56.432Z", "dateReserved": "2026-07-19T07:54:57.020Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-07-19T14:55:23.539Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

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"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().\n\nAfter patch 1/2 in this series, vti6_update() unlinks and relinks\nthe tunnel through t->net. vti6_siocdevprivate() still uses\ndev_net(dev) for the collision lookup. For a tunnel moved through\nIFLA_NET_NS_FD, dev_net(dev) is the new netns, not t->net.\n\nSIOCCHGTUNNEL on a migrated tunnel then runs:\n\n net = dev_net(dev) /* migrated netns */\n t = vti6_locate(net, &p1, false) /* misses target in t->net */\n ...\n t = netdev_priv(dev)\n vti6_update(t, &p1, false) /* mutates t->net's hash */\n\nA caller in the migrated netns picks params that match a tunnel\nin the creation netns. The lookup in dev_net(dev) finds nothing.\nvti6_update() prepends the migrated tunnel at the head of the\ncreation netns hash bucket for those params. Later lookups in\nthe creation netns resolve to the migrated device. xfrm receive\ndelivers the matched packets through a device the caller controls.\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net). Cross tenant scope on container hosts.\n\nSwitch the SIOCCHGTUNNEL path on a non fallback device to use\nt->net for the lookup. The lookup now matches the netns\nvti6_update() operates on.\n\nAlso add ns_capable(self->net->user_ns, CAP_NET_ADMIN) before\nthe lookup. The check at the top of the case is against\ndev_net(dev)->user_ns, which after migration is the attacker's\nnetns. A caller there can pick params absent from self->net,\nthe lookup returns NULL, t becomes self, and vti6_update()\ninserts the device into the creation netns hash. The new check\nrequires CAP_NET_ADMIN in the creation netns user_ns too.\n\nSIOCADDTUNNEL and SIOCCHGTUNNEL on the fallback device keep\ndev_net(dev), which equals init_net there."}], "id": "CVE-2026-63921", "lastModified": "2026-10-27T12:54:08.507", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-63921", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:33:25.874966Z", "version": "2.0.3"}}]}, "published": "2026-07-19T16:17:10.300", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/1acfb7d9c6fc7e209ed7789392697e97e03edd33"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/44d2ff7d2178503b93151140a45dfa2ad49c9906"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/596f6354c96a891e58c04a09cbfb7b0d1ec00dab"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/853f6ea482dfcd3404bbef458ab4d68364eed838"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8b484efd5cb4eeef9021a661e198edc5349dacf6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/94ff740a7f9ef5c010784a325dca00cbf228f941"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d2236348414bdd6558385f35aa7fdc9bf5634011"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/df42ac708acc3399bbb6dc5ca16e0540adda7bbf"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-862"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate()", "id": "2502368", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502368"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-653", "details": ["A flaw was found in the Linux kernel's IPv6 Virtual Tunnel Interface (VTI) module. When a VTI tunnel device is moved to a different network environment, an unprivileged user in a separate user space can manipulate tunnel parameters. This manipulation could allow the user to intercept or redirect network traffic intended for other parts of the system or other containers, leading to unauthorized information disclosure or denial of service across different tenants on a container host."], "name": "CVE-2026-63921", "package_state": [{"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "impact": "important", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-63921\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-63921\nhttps://lore.kernel.org/linux-cve-announce/2026071948-CVE-2026-63921-ea11@gregkh/T"], "threat_severity": "Important"}

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