« Volver al listado

CVE-2026-40394

Estado: AnalizadaAlta (7.5)—

Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a "workspace overflow" denial of service (daemon panic) for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the HTTP/1 request is repurposed as stream zero. During the upgrade, a buffer allocation is made to reserve space to send frames to the client. This allocation would split the original workspace, and depending on the amount of prefetched data, the next fetch could perform a pipelining operation that would run out of workspace.

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.

Varnish Cache accesible en red (AV:N, PR:N, UI:N) permite denegación de servicio por desbordamiento de workspace en HTTP/2, causando pánico del daemon; CWE-670 (incorrecto uso de recursos).

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

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (2)

Varnish-software — Varnish EnterpriseVinyl-cache — Vinyl Cache

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-40394",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-40394",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-04-13T15:45:49.035659Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "cve@mitre.org",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 4,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.2
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "varnish-software",
          "product": "Varnish Cache",
          "versions": [
            {
              "status": "affected",
              "version": "9.0.0",
              "lessThan": "9.0.1",
              "versionType": "semver"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-04-12T20:16:17.857",
  "references": [
    {
      "url": "https://docs.varnish-software.com/security/VEV00002/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve@mitre.org"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cve@mitre.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-670"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a \"workspace overflow\" denial of service (daemon panic) for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the HTTP/1 request is repurposed as stream zero. During the upgrade, a buffer allocation is made to reserve space to send frames to the client. This allocation would split the original workspace, and depending on the amount of prefetched data, the next fetch could perform a pipelining operation that would run out of workspace."
    }
  ],
  "lastModified": "2026-06-17T10:45:14.147",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E53A64C0-FC22-40B5-8C3B-6288B44AC3FC",
              "versionEndIncluding": "6.0.15"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F24D68B5-362E-4797-B6DE-C19A2893186C"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r10:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "910BAD01-26E5-4D12-AA23-0BD2D48F229C"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "05E529DF-DEE1-4A62-998B-CA312DF888FD"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8AB27B34-2951-4755-851C-7C942DAFB6C7"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "18A22D42-B038-4E09-92DD-8AFD2F51A340"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FE76D616-3AA8-4D9A-9D41-9AE35FE20DBC"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9C5610CF-1FE4-4DF8-8D49-7C0CCF0359E4"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "27B776B2-9C38-45BE-89E4-ECDEEAE538A9"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r8:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "ED3CA600-C88D-4825-8C36-E052822AF59F"
            },
            {
              "criteria": "cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r9:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6B1D57B1-9771-4195-9EE3-B26EA776FB6B"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:vinyl-cache:vinyl_cache:9.0.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9868204A-88AD-46D2-BE0B-92FF686B7DE4"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}