FKIE_CVE-2026-48818

Vulnerability from fkie_nvd - Published: 2026-06-17 19:18 - Updated: 2026-06-17 20:17
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and earlier, StaticFiles on Windows is vulnerable to SSRF. An UNC path such as \\attacker.com\share can cause os.path.realpath to initiate an outbound SMB connection before the path is rejected, exposing the service account’s NTLMv2 credentials for offline cracking or relay even though the HTTP response is only a 404. The issue affects default follow_symlink=False deployments, including frameworks built on Starlette such as FastAPI; POSIX systems and follow_symlink=True are unaffected. The issue is fixed in 1.1.0.
References
security-advisories@github.comhttps://github.com/Kludex/starlette/commit/fd53168a7767b6b55ba5af787fd88f49e33cabc5
security-advisories@github.comhttps://github.com/Kludex/starlette/pull/3287
security-advisories@github.comhttps://github.com/Kludex/starlette/releases/tag/1.1.0
security-advisories@github.comhttps://github.com/Kludex/starlette/security/advisories/GHSA-wqp7-x3pw-xc5r
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "starlette",
          "vendor": "Kludex",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.1.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and earlier, StaticFiles on Windows is vulnerable to SSRF. An UNC path such as \\\\attacker.com\\share can cause os.path.realpath to initiate an outbound SMB connection before the path is rejected, exposing the service account\u2019s NTLMv2 credentials for offline cracking or relay even though the HTTP response is only a 404. The issue affects default follow_symlink=False deployments, including frameworks built on Starlette such as FastAPI; POSIX systems and follow_symlink=True are unaffected. The issue is fixed in 1.1.0."
    }
  ],
  "id": "CVE-2026-48818",
  "lastModified": "2026-06-17T20:17:22.583",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "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-2026-48818",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-17T19:31:32.312592Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-17T19:18:09.807",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/commit/fd53168a7767b6b55ba5af787fd88f49e33cabc5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/pull/3287"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/releases/tag/1.1.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Kludex/starlette/security/advisories/GHSA-wqp7-x3pw-xc5r"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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