{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-64525",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64525",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-07-25T09:20:49.256Z",
    "updatedAt": "2026-07-25T09:20:49.256Z",
    "importedAt": "2026-10-24T01:58:25.636Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit\n\nThe struct pernet_operations docstring in include/net/net_namespace.h\nexplicitly warns against blocking RCU primitives in .exit handlers:\n\n    Exit methods using blocking RCU primitives, such as\n    synchronize_rcu(), should be implemented via exit_batch.\n    [...]\n    Please, avoid synchronize_rcu() at all, where it's possible.\n\n    Note that a combination of pre_exit() and exit() can\n    be used, since a synchronize_rcu() is guaranteed between\n    the calls.\n\nxfrm_policy_fini() violates this: it calls synchronize_rcu() before\nfreeing the policy_bydst hash tables (so no RCU reader is mid-\ntraversal at free time), but runs from xfrm_net_ops.exit -- once per\nnamespace -- so a cleanup_net() of N namespaces pays N full RCU\ngrace periods serially.\n\nUse the documented pre_exit/exit split. Move the policy flush (and\nthe workqueue drains it depends on) into a new .pre_exit handler;\nxfrm_policy_fini() then runs in .exit and frees the hash tables\nafter the synchronize_rcu_expedited() that cleanup_net() guarantees\nbetween the two phases. Providing O(1) RCU grace periods per batch\ninstead of O(N).\n\nObserved on Linux 6.18 with a workload doing unshare(CLONE_NEWNET)\nat ~13/sec sustained: cleanup_net() and the netns_wq rescuer kthread\nboth stuck in xfrm_policy_fini()'s synchronize_rcu(), >300k struct\nnet accumulated in the cleanup queue, Percpu in /proc/meminfo climbed\nto 130+ GB on 256-CPU hosts, and memcg OOMs followed. setup_net and\n__put_net counts were balanced, ruling out a refcount leak.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "438b1f668ad58f46ce699bb48e4698a7839e3f9e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bca6386dc08750fc7cdcbc7683473748ba3114b9"
            },
            {
              "version": "3733fce2871c9bca9dd18a1a23b1432ea215a094",
              "status": "affected",
              "versionType": "git",
              "lessThan": "91cc13978ab0bc6f669139f53e7e613a860d10e0"
            },
            {
              "version": "069daad4f2ae9c5c108131995529d5f02392c446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d14ae8ef88c2c6590e107db61b6adce148cec7b3"
            },
            {
              "version": "069daad4f2ae9c5c108131995529d5f02392c446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3e52417318473782012b236d0325bf7d2266a597"
            },
            {
              "version": "b66920a3348c0f63ba18365248fa21fbf0b3a937",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "33a3149dd81a1e2f52b80ee1e0fc380b39f3d028",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.12.83",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.93"
            },
            {
              "version": "6.18.24",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.18.35"
            },
            {
              "version": "6.6.136",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.7"
            },
            {
              "version": "6.19.14",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.20"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "7.0",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "7.0"
            },
            {
              "version": "6.12.93",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.35",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.0.12",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "version": "7.1",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}