FKIE_CVE-2025-62727

Vulnerability from fkie_nvd - Published: 2025-10-28 21:15 - Updated: 2026-10-08 11:10
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
Starlette is a lightweight ASGI framework/toolkit. Starting in version 0.39.0 and prior to version 0.49.1 , an unauthenticated attacker can send a crafted HTTP Range header that triggers quadratic-time processing in Starlette's FileResponse Range parsing/merging logic. This enables CPU exhaustion per request, causing denial‑of‑service for endpoints serving files (e.g., StaticFiles or any use of FileResponse). This vulnerability is fixed in 0.49.1.
References
security-advisories@github.comhttps://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5
security-advisories@github.comhttps://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c
security-advisories@github.comhttps://github.com/Kludex/starlette/releases/tag/0.49.1
security-advisories@github.comhttps://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "starlette",
          "vendor": "Kludex",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.39.0, \u003c 0.49.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Starlette is a lightweight ASGI framework/toolkit. Starting in version 0.39.0 and prior to version 0.49.1 , an unauthenticated attacker can send a crafted HTTP Range header that triggers quadratic-time processing in Starlette\u0027s FileResponse Range parsing/merging logic. This enables CPU exhaustion per request, causing denial\u2011of\u2011service for endpoints serving files (e.g., StaticFiles or any use of FileResponse). This vulnerability is fixed in 0.49.1."
    },
    {
      "lang": "es",
      "value": "Starlette es un framework/toolkit ASGI ligero. A partir de la versi\u00f3n 0.39.0 y antes de la versi\u00f3n 0.49.1, un atacante no autenticado puede enviar una cabecera HTTP Range manipulada que desencadena un procesamiento de tiempo cuadr\u00e1tico en la l\u00f3gica de an\u00e1lisis/fusi\u00f3n de rangos de FileResponse de Starlette. Esto permite el agotamiento de la CPU por solicitud, causando denegaci\u00f3n de servicio para los puntos finales que sirven archivos (por ejemplo, StaticFiles o cualquier uso de FileResponse). Esta vulnerabilidad est\u00e1 corregida en la versi\u00f3n 0.49.1."
    }
  ],
  "id": "CVE-2025-62727",
  "lastModified": "2026-10-08T11:10:00.250",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-62727",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-10-28T20:36:34.130234Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-10-28T21:15:40.447",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/releases/tag/0.49.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-407"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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