{
  "threat_severity" : "Moderate",
  "public_date" : "2026-06-25T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()",
    "id" : "2492779",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2492779"
  },
  "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-364",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it. Use __xfrm_policy_inexact_prune_bin() directly since\nthe lock is already held. The wrapper xfrm_policy_inexact_prune_bin()\nbecomes unused and is removed.\nRace:\nCPU0 (XFRM_MSG_DELPOLICY)           CPU1 (XFRM_MSG_NEWSPDINFO)\n==========================          ==========================\nxfrm_policy_bysel_ctx():\nspin_lock_bh(xfrm_policy_lock)\nbin = xfrm_policy_inexact_lookup()\n__xfrm_policy_unlink(pol)\nspin_unlock_bh(xfrm_policy_lock)\nxfrm_policy_kill(ret)\n// wide window, lock not held\nxfrm_hash_rebuild():\nspin_lock_bh(xfrm_policy_lock)\n__xfrm_policy_inexact_flush():\nkfree_rcu(bin)  // bin freed\nspin_unlock_bh(xfrm_policy_lock)\nxfrm_policy_inexact_prune_bin(bin)\n// UAF: bin is freed", "A flaw was found in the Linux kernel. A race condition exists in the `xfrm` policy handling, specifically within the `xfrm_policy_bysel_ctx()` function. This flaw allows for a use-after-free vulnerability, where memory is accessed after it has been released. This can lead to system instability or a denial of service (DoS), making the system unresponsive or causing it to crash." ],
  "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" : "Out of support scope",
    "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 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"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-53239\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53239\nhttps://lore.kernel.org/linux-cve-announce/2026062510-CVE-2026-53239-8ebc@gregkh/T" ],
  "name" : "CVE-2026-53239",
  "csaw" : false
}