FKIE_CVE-2026-16117

Vulnerability from fkie_nvd - Published: 2026-07-18 14:17 - Updated: 2026-07-21 18:31
Severity
10.0 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Summary
Impact: @fastify/http-proxy versions up to and including 11.5.0 fail to rewrite the request prefix when the prefix segment is URL-encoded. Fastify's router URL-decodes paths for route matching, but request.url retains the original encoded form, and the prefix-rewrite step uses a literal string replace against the decoded prefix. A request that encodes one or more characters of the configured prefix therefore matches the route but skips the rewrite, so the raw encoded path is forwarded to the upstream unchanged. The upstream then decodes the path and serves it, letting an attacker reach upstream paths that the proxy was configured to hide via rewritePrefix, including internal or administrative endpoints. Patches: upgrade to @fastify/http-proxy 11.6.0. Workarounds: none.
References
ce714d77-add3-4f53-aff5-83d477b104bbhttps://cna.openjsf.org/security-advisories.html
ce714d77-add3-4f53-aff5-83d477b104bbhttps://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-mx7v-qhg9-2mvv
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/@fastify/http-proxy",
          "product": "@fastify/http-proxy",
          "vendor": "@fastify/http-proxy",
          "versions": [
            {
              "lessThan": "11.6.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "11.6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Impact: @fastify/http-proxy versions up to and including 11.5.0 fail to rewrite the request prefix when the prefix segment is URL-encoded. Fastify\u0027s router URL-decodes paths for route matching, but request.url retains the original encoded form, and the prefix-rewrite step uses a literal string replace against the decoded prefix. A request that encodes one or more characters of the configured prefix therefore matches the route but skips the rewrite, so the raw encoded path is forwarded to the upstream unchanged. The upstream then decodes the path and serves it, letting an attacker reach upstream paths that the proxy was configured to hide via rewritePrefix, including internal or administrative endpoints.\n\nPatches: upgrade to @fastify/http-proxy 11.6.0.\n\nWorkarounds: none."
    }
  ],
  "id": "CVE-2026-16117",
  "lastModified": "2026-07-21T18:31:51.680",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.8,
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-16117",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-20T15:14:37.517621Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-18T14:17:11.620",
  "references": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "url": "https://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-mx7v-qhg9-2mvv"
    }
  ],
  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "type": "Secondary"
    }
  ]
}



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