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CVE-2026-74590

Estado: RecibidaAlta (7.8)—

In the Linux kernel, the following vulnerability has been resolved:

fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions

The BPF verifier and the dynptr abstraction ensure that the memory space referenced by a dynptr remains valid. They do not, however, provide any guarantee that the contents of the memory are stable. kfuncs are expected to remain memory-safe even if concurrent modifications occur.

bpf_get_fsverity_digest() didn't follow that: it could crash if arg->digest_size was concurrently modified.

Fix that by using the known-good value hash_alg->digest_size instead.

Also widen 'dynptr_sz' and 'out_digest_sz' to u64 to match the return type of __bpf_dynptr_size().

Leer descripción completaMostrar menos

It doesn't appear that it can actually be more than INT_MAX currently (since __bpf_dynptr_data_rw() excludes file-based pointers), but the correct type might as well be used.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad de escalada de privilegios en el kernel Linux (AV:L, PR:L) exploitable por un usuario local para causar crash (DoS) mediante modificación concurrente de memoria en bpf_get_fsverity_digest().

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-74590",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "67814c00de3161181cddd06c77aeaf86ac4cc584",
              "lessThan": "1344b632cb5043e32939a84568125719111c5af3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "67814c00de3161181cddd06c77aeaf86ac4cc584",
              "lessThan": "2a5cfcad1d56e26d645b7887b0ed24c371851525",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "67814c00de3161181cddd06c77aeaf86ac4cc584",
              "lessThan": "5bd63cad9df4328a184c409fbdad4f17944bcdb8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "67814c00de3161181cddd06c77aeaf86ac4cc584",
              "lessThan": "3e8ec7c0387273329374f5c7bd61f5f38af71fe1",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/verity/measure.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/verity/measure.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:31.243",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1344b632cb5043e32939a84568125719111c5af3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2a5cfcad1d56e26d645b7887b0ed24c371851525",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3e8ec7c0387273329374f5c7bd61f5f38af71fe1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5bd63cad9df4328a184c409fbdad4f17944bcdb8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfsverity: Fix bpf_get_fsverity_digest() dynptr assumptions\n\nThe BPF verifier and the dynptr abstraction ensure that the memory space\nreferenced by a dynptr remains valid.  They do not, however, provide any\nguarantee that the contents of the memory are stable.  kfuncs are\nexpected to remain memory-safe even if concurrent modifications occur.\n\nbpf_get_fsverity_digest() didn't follow that: it could crash if\narg->digest_size was concurrently modified.\n\nFix that by using the known-good value hash_alg->digest_size instead.\n\nAlso widen 'dynptr_sz' and 'out_digest_sz' to u64 to match the return\ntype of __bpf_dynptr_size().  It doesn't appear that it can actually be\nmore than INT_MAX currently (since __bpf_dynptr_data_rw() excludes\nfile-based pointers), but the correct type might as well be used."
    }
  ],
  "lastModified": "2026-08-25T06:18:34.113",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}