{
  "threat_severity" : "Important",
  "public_date" : "2026-05-01T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach()",
    "id" : "2464397",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2464397"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.3",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-843",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach()\nSashiko AI-review observed:\nIn ip6_err_gen_icmpv6_unreach(), the skb is an outer IPv4 ICMP error packet\nwhere its cb contains an IPv4 inet_skb_parm. When skb is cloned into skb2\nand passed to icmp6_send(), it uses IP6CB(skb2).\nIP6CB interprets the IPv4 inet_skb_parm as an inet6_skb_parm. The cipso\noffset in inet_skb_parm.opt directly overlaps with dsthao in inet6_skb_parm\nat offset 18.\nIf an attacker sends a forged ICMPv4 error with a CIPSO IP option, dsthao\nwould be a non-zero offset. Inside icmp6_send(), mip6_addr_swap() is called\nand uses ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO).\nThis would scan the inner, attacker-controlled IPv6 packet starting at that\noffset, potentially returning a fake TLV without checking if the remaining\npacket length can hold the full 18-byte struct ipv6_destopt_hao.\nCould mip6_addr_swap() then perform a 16-byte swap that extends past the end\nof the packet data into skb_shared_info?\nShould the cb array also be cleared in ip6_err_gen_icmpv6_unreach() and\nip6ip6_err() to prevent this?\nThis patch implements the first suggestion.\nI am not sure if ip6ip6_err() needs to be changed.\nA separate patch would be better anyway.", "A flaw was found in the Linux kernel's IPv6 ICMP error generation. A remote attacker could send a specially crafted IPv4 ICMP error packet with a Common Internet Protocol Security Option (CIPSO) IP option. This could lead to incorrect handling of packet control block data when generating an IPv6 ICMP error, potentially causing an out-of-bounds memory access. This memory corruption could result in information disclosure or a denial of service." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "release_date" : "2026-06-08T00:00:00Z",
    "advisory" : "RHSA-2026:24343",
    "cpe" : "cpe:/o:redhat:enterprise_linux_eus:10.0",
    "package" : "kernel-0:6.12.0-55.77.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-06-10T00:00:00Z",
    "advisory" : "RHSA-2026:25120",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.132.1.rt7.473.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-06-10T00:00:00Z",
    "advisory" : "RHSA-2026:25121",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.132.1.el8_10"
  }, {
    "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" : "2026-06-12T00:00:00Z",
    "advisory" : "RHSA-2026:25533",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.195.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-06-12T00:00:00Z",
    "advisory" : "RHSA-2026:25533",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.6",
    "package" : "kernel-0:4.18.0-372.195.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "release_date" : "2026-06-04T00:00:00Z",
    "advisory" : "RHSA-2026:22964",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.8",
    "package" : "kernel-0:4.18.0-477.145.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "release_date" : "2026-06-04T00:00:00Z",
    "advisory" : "RHSA-2026:22964",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.8",
    "package" : "kernel-0:4.18.0-477.145.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-06-03T00:00:00Z",
    "advisory" : "RHSA-2026:22940",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.174.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-06-03T00:00:00Z",
    "advisory" : "RHSA-2026:22900",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.174.1.rt14.459.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions",
    "release_date" : "2026-06-04T00:00:00Z",
    "advisory" : "RHSA-2026:23237",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.4",
    "package" : "kernel-0:5.14.0-427.129.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-06-04T00:00:00Z",
    "advisory" : "RHSA-2026:23224",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "kernel-0:5.14.0-570.119.1.el9_6"
  } ],
  "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" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "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"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-43038\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43038\nhttps://lore.kernel.org/linux-cve-announce/2026050103-CVE-2026-43038-b591@gregkh/T" ],
  "name" : "CVE-2026-43038",
  "csaw" : false
}