{
  "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-2025-37797",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-37797",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-05-02T14:16:01.905Z",
    "updatedAt": "2026-08-05T11:57:36.042Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "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_sched: hfsc: Fix a UAF vulnerability in class handling",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: hfsc: Fix a UAF vulnerability in class handling\n\nThis patch fixes a Use-After-Free vulnerability in the HFSC qdisc class\nhandling. The issue occurs due to a time-of-check/time-of-use condition\nin hfsc_change_class() when working with certain child qdiscs like netem\nor codel.\n\nThe vulnerability works as follows:\n1. hfsc_change_class() checks if a class has packets (q.qlen != 0)\n2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g.,\n   codel, netem) might drop packets and empty the queue\n3. The code continues assuming the queue is still non-empty, adding\n   the class to vttree\n4. This breaks HFSC scheduler assumptions that only non-empty classes\n   are in vttree\n5. Later, when the class is destroyed, this can lead to a Use-After-Free\n\nThe fix adds a second queue length check after qdisc_peek_len() to verify\nthe queue wasn't emptied.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "28b09a067831f7317c3841812276022d6c940677"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "39b9095dd3b55d9b2743df038c32138efa34a9de"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "fcc8ede663569c704fb00a702973bd6c00373283"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "20d584a33e480ae80d105f43e0e7b56784da41b9"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3aa852e3605000d5c47035c3fc3a986d14ccfa9f"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "86cd4641c713455a4f1c8e54c370c598c2b1cee0"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bb583c88d23b72d8d16453d24856c99bd93dadf5"
            },
            {
              "version": "21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3df275ef0a6ae181e8428a6589ef5d5231e58b5c"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.14",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.14"
            },
            {
              "version": "5.4.293",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.237",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.181",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.136",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.89",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.26",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.14.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.14.*"
            },
            {
              "version": "6.15",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}