{
  "threat_severity" : "Moderate",
  "public_date" : "2026-05-06T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: netfilter: ctnetlink: ensure safe access to master conntrack",
    "id" : "2467005",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2467005"
  },
  "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" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnetfilter: ctnetlink: ensure safe access to master conntrack\nHolding reference on the expectation is not sufficient, the master\nconntrack object can just go away, making exp->master invalid.\nTo access exp->master safely:\n- Grab the nf_conntrack_expect_lock, this gets serialized with\nclean_from_lists() which also holds this lock when the master\nconntrack goes away.\n- Hold reference on master conntrack via nf_conntrack_find_get().\nNot so easy since the master tuple to look up for the master conntrack\nis not available in the existing problematic paths.\nThis patch goes for extending the nf_conntrack_expect_lock section\nto address this issue for simplicity, in the cases that are described\nbelow this is just slightly extending the lock section.\nThe add expectation command already holds a reference to the master\nconntrack from ctnetlink_create_expect().\nHowever, the delete expectation command needs to grab the spinlock\nbefore looking up for the expectation. Expand the existing spinlock\nsection to address this to cover the expectation lookup. Note that,\nthe nf_ct_expect_iterate_net() calls already grabs the spinlock while\niterating over the expectation table, which is correct.\nThe get expectation command needs to grab the spinlock to ensure master\nconntrack does not go away. This also expands the existing spinlock\nsection to cover the expectation lookup too. I needed to move the\nnetlink skb allocation out of the spinlock to keep it GFP_KERNEL.\nFor the expectation events, the IPEXP_DESTROY event is already delivered\nunder the spinlock, just move the delivery of IPEXP_NEW under the\nspinlock too because the master conntrack event cache is reached through\nexp->master.\nWhile at it, add lockdep notations to help identify what codepaths need\nto grab the spinlock.", "A flaw was found in the `netfilter: ctnetlink` component of the Linux kernel. This vulnerability occurs due to insufficient locking when accessing the master conntrack object, allowing it to become invalid while still being referenced. A local attacker could potentially exploit this race condition, leading to a system crash and a denial of service." ],
  "statement" : "ctnetlink expectation handling could keep a reference to the expectation object while the associated master conntrack object was freed concurrently. This leaves exp master as a stale pointer and can let get, delete, or event reporting paths access master conntrack state after it has gone away. For the CVSS the PR:L is used in the paranoid score because some deployments delegate CAP_NET_ADMIN or conntrack management inside network namespaces or containers to less privileged local users. The issue is not directly network reachable as a remote packet only attack, although traffic and conntrack activity can help create the concurrent state needed for the race. In the paranoid case, the stale master conntrack pointer is treated as a use after free candidate with possible confidentiality and integrity impact.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2026-05-28T00:00:00Z",
    "advisory" : "RHSA-2026:21557",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.2",
    "package" : "kernel-0:6.12.0-211.18.1.el10_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "release_date" : "2026-06-22T00:00:00Z",
    "advisory" : "RHSA-2026:27731",
    "cpe" : "cpe:/o:redhat:enterprise_linux_eus:10.0",
    "package" : "kernel-0:6.12.0-55.82.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26535",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.4",
    "package" : "kernel-0:4.18.0-305.194.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26535",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.4",
    "package" : "kernel-0:4.18.0-305.194.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26570",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.196.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26570",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.6",
    "package" : "kernel-0:4.18.0-372.196.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26563",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.8",
    "package" : "kernel-0:4.18.0-477.147.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26563",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.8",
    "package" : "kernel-0:4.18.0-477.147.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-06-11T00:00:00Z",
    "advisory" : "RHSA-2026:25217",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.15.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-06-11T00:00:00Z",
    "advisory" : "RHSA-2026:25217",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.15.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26515",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.176.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-06-17T00:00:00Z",
    "advisory" : "RHSA-2026:26462",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.176.1.rt14.461.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions",
    "release_date" : "2026-06-22T00:00:00Z",
    "advisory" : "RHSA-2026:27735",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.4",
    "package" : "kernel-0:5.14.0-427.132.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-06-22T00:00:00Z",
    "advisory" : "RHSA-2026:27708",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "kernel-0:5.14.0-570.123.1.el9_6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Under investigation",
    "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-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-43116\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43116\nhttps://lore.kernel.org/linux-cve-announce/2026050626-CVE-2026-43116-08a5@gregkh/T" ],
  "name" : "CVE-2026-43116",
  "mitigation" : {
    "value" : "Mitigation for this issue is to skip loading the affected module \"netfilter\" onto the system till we have a fix available, this can be done by a blacklist mechanism, this will ensure the driver is not loaded at the boot time.\n~~~\nHow do I blacklist a kernel module to prevent it from loading automatically?\nhttps://access.redhat.com/solutions/41278 \n~~~",
    "lang" : "en:us"
  },
  "csaw" : false
}