{
  "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-2021-47131",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47131",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-03-15T20:14:34.647Z",
    "updatedAt": "2026-08-05T08:46:13.224Z",
    "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": "net/tls: Fix use-after-free after the TLS device goes down and up",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix use-after-free after the TLS device goes down and up\n\nWhen a netdev with active TLS offload goes down, tls_device_down is\ncalled to stop the offload and tear down the TLS context. However, the\nsocket stays alive, and it still points to the TLS context, which is now\ndeallocated. If a netdev goes up, while the connection is still active,\nand the data flow resumes after a number of TCP retransmissions, it will\nlead to a use-after-free of the TLS context.\n\nThis commit addresses this bug by keeping the context alive until its\nnormal destruction, and implements the necessary fallbacks, so that the\nconnection can resume in software (non-offloaded) kTLS mode.\n\nOn the TX side tls_sw_fallback is used to encrypt all packets. The RX\nside already has all the necessary fallbacks, because receiving\nnon-decrypted packets is supported. The thing needed on the RX side is\nto block resync requests, which are normally produced after receiving\nnon-decrypted packets.\n\nThe necessary synchronization is implemented for a graceful teardown:\nfirst the fallbacks are deployed, then the driver resources are released\n(it used to be possible to have a tls_dev_resync after tls_dev_del).\n\nA new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback\nmode. It's used to skip the RX resync logic completely, as it becomes\nuseless, and some objects may be released (for example, resync_async,\nwhich is allocated and freed by the driver).",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "e8f69799810c32dd40c6724d829eccc70baad07f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f1d4184f128dede82a59a841658ed40d4e6d3aa2"
            },
            {
              "version": "e8f69799810c32dd40c6724d829eccc70baad07f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0f1e6fe66977a864fe850522316f713d7b926fd9"
            },
            {
              "version": "e8f69799810c32dd40c6724d829eccc70baad07f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c55dcdd435aa6c6ad6ccac0a4c636d010ee367a4"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.18",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.18"
            },
            {
              "version": "5.10.43",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.12.10",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.12.*"
            },
            {
              "version": "5.13",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}