{
  "threat_severity" : "Important",
  "public_date" : "2026-07-19T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: ip6: vti: Use ip6_tnl.net in vti6_changelink()",
    "id" : "2502434",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2502434"
  },
  "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-825",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nip6: vti: Use ip6_tnl.net in vti6_changelink().\nip netns add ns1\nip netns add ns2\nip -n ns1 link add vti6_test type vti6 remote ::1 local ::2 key 7\nip -n ns1 link set vti6_test netns ns2\nip -n ns2 link set vti6_test type vti6 remote ::3 local ::4 key 9\nip netns del ns2\nip netns del ns1\n[  132.495484] ------------[ cut here ]------------\n[  132.497609] kernel BUG at net/core/dev.c:12376!\nCommit 61220ab34948 (\"vti6: Enable namespace changing\") dropped\nNETIF_F_NETNS_LOCAL from vti6 devices. A vti6 tunnel can then\nmove through IFLA_NET_NS_FD. After the move dev_net(dev) points\nat the new netns while t->net stays at the creation netns.\nvti6_changelink() and vti6_update() still use dev_net(dev) and\ndev_net(t->dev). They unlink from one per netns hash and relink\ninto another. The creation netns is left with a stale entry.\ncleanup_net() of that netns later walks freed memory.\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net). Cross tenant scope on container hosts.", "A flaw was found in the Linux kernel's IPv6 Virtual Tunnel Interface (vti6) component. An unprivileged local user, particularly within a user namespace, could exploit a vulnerability related to incorrect network namespace handling during the movement of a vti6 tunnel. This issue can lead to a kernel bug, resulting in a denial of service (system crash) and potentially impacting container isolation on affected hosts." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Hardened Images",
    "fix_state" : "Not affected",
    "package_name" : "erlang27",
    "cpe" : "cpe:/a:redhat:hummingbird:1",
    "impact" : "important"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-63917\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-63917\nhttps://lore.kernel.org/linux-cve-announce/2026071947-CVE-2026-63917-4a8f@gregkh/T" ],
  "name" : "CVE-2026-63917",
  "csaw" : false
}