{
  "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-2021-47129",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47129",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-03-15T20:14:33.102Z",
    "updatedAt": "2026-08-05T08:46:11.081Z",
    "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": "netfilter: nft_ct: skip expectations for confirmed conntrack",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_ct: skip expectations for confirmed conntrack\n\nnft_ct_expect_obj_eval() calls nf_ct_ext_add() for a confirmed\nconntrack entry. However, nf_ct_ext_add() can only be called for\n!nf_ct_is_confirmed().\n\n[ 1825.349056] WARNING: CPU: 0 PID: 1279 at net/netfilter/nf_conntrack_extend.c:48 nf_ct_xt_add+0x18e/0x1a0 [nf_conntrack]\n[ 1825.351391] RIP: 0010:nf_ct_ext_add+0x18e/0x1a0 [nf_conntrack]\n[ 1825.351493] Code: 41 5c 41 5d 41 5e 41 5f c3 41 bc 0a 00 00 00 e9 15 ff ff ff ba 09 00 00 00 31 f6 4c 89 ff e8 69 6c 3d e9 eb 96 45 31 ed eb cd <0f> 0b e9 b1 fe ff ff e8 86 79 14 e9 eb bf 0f 1f 40 00 0f 1f 44 00\n[ 1825.351721] RSP: 0018:ffffc90002e1f1e8 EFLAGS: 00010202\n[ 1825.351790] RAX: 000000000000000e RBX: ffff88814f5783c0 RCX: ffffffffc0e4f887\n[ 1825.351881] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88814f578440\n[ 1825.351971] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88814f578447\n[ 1825.352060] R10: ffffed1029eaf088 R11: 0000000000000001 R12: ffff88814f578440\n[ 1825.352150] R13: ffff8882053f3a00 R14: 0000000000000000 R15: 0000000000000a20\n[ 1825.352240] FS:  00007f992261c900(0000) GS:ffff889faec00000(0000) knlGS:0000000000000000\n[ 1825.352343] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 1825.352417] CR2: 000056070a4d1158 CR3: 000000015efe0000 CR4: 0000000000350ee0\n[ 1825.352508] Call Trace:\n[ 1825.352544]  nf_ct_helper_ext_add+0x10/0x60 [nf_conntrack]\n[ 1825.352641]  nft_ct_expect_obj_eval+0x1b8/0x1e0 [nft_ct]\n[ 1825.352716]  nft_do_chain+0x232/0x850 [nf_tables]\n\nAdd the ct helper extension only for unconfirmed conntrack. Skip rule\nevaluation if the ct helper extension does not exist. Thus, you can\nonly create expectations from the first packet.\n\nIt should be possible to remove this limitation by adding a new action\nto attach a generic ct helper to the first packet. Then, use this ct\nhelper extension from follow up packets to create the ct expectation.\n\nWhile at it, add a missing check to skip the template conntrack too\nand remove check for IPCT_UNTRACK which is implicit to !ct.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "857b46027d6f91150797295752581b7155b9d0e1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "da8d31e80ff425f5a65dab7060d5c4aba749e562"
            },
            {
              "version": "857b46027d6f91150797295752581b7155b9d0e1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5f3429c05e4028a0e241afdad856dd15dec2ffb9"
            },
            {
              "version": "857b46027d6f91150797295752581b7155b9d0e1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2c0e6b35b88a961127066a1028bce9c727cbc3e5"
            },
            {
              "version": "857b46027d6f91150797295752581b7155b9d0e1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1710eb913bdcda3917f44d383c32de6bdabfc836"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.3",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.3"
            },
            {
              "version": "5.4.125",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "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": "*"
            }
          ]
        }
      ]
    }
  }
}