{
  "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-2021-47506",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47506",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-24T15:01:52.746Z",
    "updatedAt": "2026-08-05T08:48:10.240Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "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": "nfsd: fix use-after-free due to delegation race",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix use-after-free due to delegation race\n\nA delegation break could arrive as soon as we've called vfs_setlease.  A\ndelegation break runs a callback which immediately (in\nnfsd4_cb_recall_prepare) adds the delegation to del_recall_lru.  If we\nthen exit nfs4_set_delegation without hashing the delegation, it will be\nfreed as soon as the callback is done with it, without ever being\nremoved from del_recall_lru.\n\nSymptoms show up later as use-after-free or list corruption warnings,\nusually in the laundromat thread.\n\nI suspect aba2072f4523 \"nfsd: grant read delegations to clients holding\nwrites\" made this bug easier to hit, but I looked as far back as v3.0\nand it looks to me it already had the same problem.  So I'm not sure\nwhere the bug was introduced; it may have been there from the beginning.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "04a8d07f3d58308b92630045560799a3faa3ebce"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "348714018139c39533c55661a0c7c990671396b4"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "33645d3e22720cac1e4548f8fef57bf0649536ee"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2becaa990b93cbd2928292c0b669d3abb6cf06d4"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e0759696de6851d7536efddfdd2dfed4c4df1f09"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "eeb0711801f5e19ef654371b627682aed3b11373"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "148c816f10fd11df27ca6a9b3238cdd42fa72cd3"
            },
            {
              "version": "dff1399f8addf7129c49bb2227469da79cc30b47",
              "status": "affected",
              "versionType": "git",
              "lessThan": "548ec0805c399c65ed66c6641be467f717833ab5"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "3.17",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "3.17"
            },
            {
              "version": "4.4.296",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.4.*"
            },
            {
              "version": "4.9.294",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.9.*"
            },
            {
              "version": "4.14.259",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.14.*"
            },
            {
              "version": "4.19.222",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.168",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.85",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.8",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "5.16",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}