{
  "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-2025-21921",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-21921",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-04-01T15:40:55.110Z",
    "updatedAt": "2026-05-11T21:09:06.682Z",
    "importedAt": "2026-10-24T01:57:29.455Z",
    "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: ethtool: netlink: Allow NULL nlattrs when getting a phy_device",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ethtool: netlink: Allow NULL nlattrs when getting a phy_device\n\nethnl_req_get_phydev() is used to lookup a phy_device, in the case an\nethtool netlink command targets a specific phydev within a netdev's\ntopology.\n\nIt takes as a parameter a const struct nlattr *header that's used for\nerror handling :\n\n       if (!phydev) {\n               NL_SET_ERR_MSG_ATTR(extack, header,\n                                   \"no phy matching phyindex\");\n               return ERR_PTR(-ENODEV);\n       }\n\nIn the notify path after a ->set operation however, there's no request\nattributes available.\n\nThe typical callsite for the above function looks like:\n\n\tphydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_XXX_HEADER],\n\t\t\t\t      info->extack);\n\nSo, when tb is NULL (such as in the ethnl notify path), we have a nice\ncrash.\n\nIt turns out that there's only the PLCA command that is in that case, as\nthe other phydev-specific commands don't have a notification.\n\nThis commit fixes the crash by passing the cmd index and the nlattr\narray separately, allowing NULL-checking it directly inside the helper.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "c15e065b46dc4e19837275b826c1960d55564abd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "639c70352958735addbba5ae7dd65985da96e061"
            },
            {
              "version": "c15e065b46dc4e19837275b826c1960d55564abd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1f458fa42c29144cef280e05bc49fc21b873d897"
            },
            {
              "version": "c15e065b46dc4e19837275b826c1960d55564abd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "637399bf7e77797811adf340090b561a8f9d1213"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.12",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.12"
            },
            {
              "version": "6.12.19",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.13.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.13.*"
            },
            {
              "version": "6.14",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}