CVE-2026-49854

{
  "id": "CVE-2026-49854",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-14T21:17:02.300",
  "lastModified": "2026-10-24T21:10:00.130",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6."
    },
    {
      "lang": "es",
      "value": "Tornado es un framework web de Python y una biblioteca de red asíncrona. Antes de la 6.5.6, la extensión nativa opcional tornado.speedups implementaba websocket_mask sin validar que el argumento mask fuera exactamente de cuatro bytes, permitiendo que la función C leyera hasta tres bytes más allá del búfer proporcionado cuando se accedía a ella a través de la decodificación de tokens XSRF de Tornado con la extensión nativa activa. Este problema se solucionó en la versión 6.5.6."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "tornadoweb",
          "product": "tornado",
          "versions": [
            {
              "version": "< 6.5.6",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-15T13:23:13.452445Z",
          "id": "CVE-2026-49854",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-126"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/tornadoweb/tornado/pull/3626",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.6",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-cx3h-4qpv-8hc9",
      "source": "[email protected]"
    }
  ]
}