{
  "threat_severity" : "Important",
  "public_date" : "2026-08-21T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net: ipv6: use-after-free in fib6_rule_suppress due to stale res->rt6 pointer",
    "id" : "2520980",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2520980"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/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:\nnet: ipv6: clear suppressed fib6 rule result\nfib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(),\nbut leaves res->rt6 pointing at the released rt6_info.\nIf no later rule supplies a replacement, fib6_rule_lookup() still sees\nres.rt6 and returns that stale dst to its caller. A suppressing rule can\ntherefore leak a released route back to rt6_lookup(), and the next put\nhits rcuref_put_slowpath() from dst_release().\nClear res->rt6 when suppressing the route so suppressed lookups fall\nthrough to the null dst instead of reusing the released one.", "A use-after-free vulnerability was found in the Linux kernel's IPv6 FIB rule lookup path. In fib6_rule_suppress(), when a route is suppressed and released via ip6_rt_put_flags(), the res->rt6 pointer is not cleared. If no later rule supplies a replacement route, fib6_rule_lookup() returns the stale (freed) rt6_info to its caller. The subsequent dst_release() then operates on freed memory, hitting rcuref_put_slowpath(). A local attacker who can configure IPv6 routing/FIB rules could trigger this to cause a denial of service (kernel crash) or potentially escalate privileges." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2026-09-04T00:00:00Z",
    "advisory" : "RHSA-2026:63128",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.2",
    "package" : "kernel-0:6.12.0-211.51.1.el10_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "release_date" : "2026-09-02T00:00:00Z",
    "advisory" : "RHSA-2026:62609",
    "cpe" : "cpe:/o:redhat:enterprise_linux_eus:10.0",
    "package" : "kernel-0:6.12.0-55.102.1.el10_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63013",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.159.1.rt7.500.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63014",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.159.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
    "release_date" : "2026-08-26T00:00:00Z",
    "advisory" : "RHSA-2026:59994",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.4",
    "package" : "kernel-0:4.18.0-305.202.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-08-26T00:00:00Z",
    "advisory" : "RHSA-2026:59994",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.4",
    "package" : "kernel-0:4.18.0-305.202.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60485",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.209.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60485",
    "cpe" : "cpe:/o:redhat:rhel_eus_long_life:8.6",
    "package" : "kernel-0:4.18.0-372.209.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "release_date" : "2026-09-01T00:00:00Z",
    "advisory" : "RHSA-2026:61932",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.8",
    "package" : "kernel-0:4.18.0-477.163.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "release_date" : "2026-09-01T00:00:00Z",
    "advisory" : "RHSA-2026:61932",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.8",
    "package" : "kernel-0:4.18.0-477.163.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-08-26T00:00:00Z",
    "advisory" : "RHSA-2026:59723",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.42.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-08-26T00:00:00Z",
    "advisory" : "RHSA-2026:59723",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.42.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60437",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.189.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60438",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.189.1.rt14.474.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60484",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.4",
    "package" : "kernel-0:5.14.0-427.147.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-08-27T00:00:00Z",
    "advisory" : "RHSA-2026:60486",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "kernel-0:5.14.0-570.136.1.el9_6"
  } ],
  "package_state" : [ {
    "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" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux for NVIDIA 26",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/a:redhat:enterprise_linux_nvidia:"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-74581\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74581\nhttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6aea62e433fe1b586202a5fee8b5807ce635e1d7" ],
  "csaw" : true,
  "name" : "CVE-2026-74581",
  "mitigation" : {
    "value" : "To mitigate this issue, disable the `ipv6` kernel module at boot using the kernel command-line parameter:\n```\ngrubby --update-kernel=ALL --args=\"ipv6.disable=1\"\n```\nA reboot is required for this change to take effect. To verify after reboot:\n```\ncat /proc/cmdline | grep -o ipv6.disable=1\nsysctl net.ipv6.conf.all.disable_ipv6\n```\nApplications or services that rely on the IPv6 protocol cannot use this mitigation and should prioritize applying the fix.",
    "lang" : "en:us"
  }
}