{"id":"CVE-2026-28791","aliases":["EUVD-2026-11609","GHSA-5hxf-c7j4-279c"],"status":"published","title":"Path Traversal in Media Upload Handle in Tina","description":"Tina is a headless content management system. Prior to 2.1.7, a path traversal vulnerability exists in the TinaCMS development server's media upload handler. The code at media.ts joins user-controlled path segments using path.join() without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem. This vulnerability is fixed in 2.1.7.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00377,"percentile":0.32099,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22"],"published":"2026-03-12T16:55:47Z","modified":"2026-10-28T02:31:01Z","fixes":[{"ecosystem":"npm","package":"tinacms","fixed_in":["2.1.7"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"tinacms","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.7"}]}]},{"source":"osv","ecosystem":"npm","package":"tinacms","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.1.7"}]}]}],"products":[{"vendor":"ssw","product":"tinacms\\/cli"},{"vendor":"tinacms","product":"tinacms"}],"references":[{"url":"https://github.com/tinacms/tinacms/security/advisories/GHSA-5hxf-c7j4-279c","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28791","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-5hxf-c7j4-279c"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28791.json","tags":["advisory"]},{"url":"https://github.com/tinacms/tinacms","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-28791","title":"Path Traversal in Media Upload Handle in Tina","description":"Tina is a headless content management system. Prior to 2.1.7, a path traversal vulnerability exists in the TinaCMS development server's media upload handler. The code at media.ts joins user-controlled path segments using path.join() without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem. This vulnerability is fixed in 2.1.7.","status":"published","published":"2026-03-12T16:55:47.528Z","modified":"2026-03-13T16:27:56.642Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:20:01.969981Z"}],"euvd":[{"id":"EUVD-2026-11609","description":"Tina is a headless content management system. Prior to 2.1.7, a path traversal vulnerability exists in the TinaCMS development server's media upload handler. The code at media.ts joins user-controlled path segments using path.join() without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem. This vulnerability is fixed in 2.1.7.","status":"published","published":"2026-03-12T16:55:47Z","modified":"2026-03-13T16:27:56Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T19:25:35.010093Z"}],"ghsa":[{"id":"GHSA-5hxf-c7j4-279c","title":"Tina: Path Traversal in Media Upload Handle","description":"## Affected Package\n\n| Field | Value |\n|-------|-------|\n| **Package** | `@tinacms/cli` |\n| **Version** | `2.0.5` (latest at time of discovery) |\n| **Vulnerable File** | `packages/@tinacms/cli/src/next/commands/dev-command/server/media.ts` |\n| **Vulnerable Lines** | 42-43 |\n\n---\n\n## Summary\n\nA **path traversal vulnerability (CWE-22)** exists in the TinaCMS development server's media upload handler. The code at `media.ts:42-43` joins user-controlled path segments using `path.join()` without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem.\n\n**Attack Vector**: Network (HTTP POST request)  \n**Impact**: Arbitrary file write, potential Remote Code Execution\n\n---\n\n## Details\n\n### Vulnerable Code Location\n\n**File**: `packages/@tinacms/cli/src/next/commands/dev-command/server/media.ts`  \n**Lines**: 42-43\n\n```typescript\nbb.on('file', async (_name, file, _info) =\u003e {\n  const fullPath = decodeURI(req.url?.slice('/media/upload/'.length));  // Line 42\n  const saveTo = path.join(mediaFolder, ...fullPath.split('/'));        // Line 43\n  // make sure the directory exists before writing the file\n  await fs.ensureDir(path.dirname(saveTo));\n  file.pipe(fs.createWriteStream(saveTo));\n});\n```\n\n### Root Cause\n\nThe `path.join()` function resolves `..` (parent directory) segments in the path. When the user-supplied path contains traversal sequences like `../../../etc/passwd`, these are resolved relative to the media folder, allowing escape to arbitrary filesystem locations.\n\n**Example**:\n```javascript\nconst mediaFolder = '/app/public/uploads';\nconst maliciousInput = '../../../tmp/evil.txt';\nconst saveTo = path.join(mediaFolder, ...maliciousInput.split('/'));\n// Result: '/tmp/evil.txt' - OUTSIDE the media folder!\n```\n\n### Additional Affected Endpoints\n\nThe same vulnerability pattern exists in:\n\n1. **Delete Handler** (`handleDelete`, lines 29-33) - Arbitrary file deletion\n2. **List Handler** (`handleList`, lines 16-27) + `MediaModel.listMedia` - Directory enumeration\n3. **MediaModel.deleteMedia** (lines 201-217) - Arbitrary file deletion\n\nSimilar code also exists in the Express version at:\n- `packages/@tinacms/cli/src/server/routes/index.ts`\n- `packages/@tinacms/cli/src/server/models/media.ts`\n\n---\n\n## PoC\n\n### Quick Verification (No Server Required)\n\nThis Node.js script directly tests the vulnerable code logic:\n\n```javascript\n#!/usr/bin/env node\n/**\n * TinaCMS Path Traversal Vulnerability - Direct Code Test\n * Run: node test-vulnerability.js\n */\n\nconst path = require('path');\nconst fs = require('fs');\n\n// Simulated configuration (matches typical TinaCMS setup)\nconst rootPath = '/tmp/tinacms-test';\nconst publicFolder = 'public';\nconst mediaRoot = 'uploads';\nconst mediaFolder = path.join(rootPath, publicFolder, mediaRoot);\n\n// Setup test directories\nfs.mkdirSync(path.join(rootPath, publicFolder, mediaRoot), { recursive: true });\nfs.mkdirSync('/tmp/target-dir', { recursive: true });\n\nconsole.log(`Media folder: ${mediaFolder}`);\n\n// Simulate vulnerable code from media.ts:42-43\nfunction vulnerableUpload(reqUrl) {\n    const fullPath = decodeURI(reqUrl.slice('/media/upload/'.length));\n    const saveTo = path.join(mediaFolder, ...fullPath.split('/'));\n    return saveTo;\n}\n\n// Test cases\nconst tests = [\n    { url: '/media/upload/image.png', desc: 'Normal upload' },\n    { url: '/media/upload/../../../tmp/target-dir/evil.txt', desc: 'Path traversal' },\n];\n\ntests.forEach(test =\u003e {\n    const result = vulnerableUpload(test.url);\n    const isVuln = !path.resolve(result).startsWith(path.resolve(mediaFolder));\n    \n    console.log(`\\n${test.desc}:`);\n    console.log(`  Input: ${test.url}`);\n    console.log(`  Result: ${result}`);\n    console.log(`  Vulnerable: ${isVuln ? 'YES ⚠️' : 'No ✓'}`);\n    \n    if (isVuln) {\n        // Actually write the file to prove it works\n        fs.mkdirSync(path.dirname(result), { recursive: true });\n        fs.writeFileSync(result, `PWNED at ${new Date().toISOString()}`);\n        console.log(`  File written: ${fs.existsSync(result)}`);\n    }\n});\n\n// Cleanup\nfs.rmSync(rootPath, { recursive: true, force: true });\n```\n\n### Output\n\n```\nMedia folder: /tmp/tinacms-test/public/uploads\n\nNormal upload:\n  Input: /media/upload/image.png\n  Result: /tmp/tinacms-test/public/uploads/image.png\n  Vulnerable: No ✓\n\nPath traversal:\n  Input: /media/upload/../../../tmp/target-dir/evil.txt\n  Result: /tmp/tmp/target-dir/evil.txt\n  Vulnerable: YES ⚠️\n  File written: true\n```\n\nThe file was successfully written to `/tmp/tmp/target-dir/evil.txt`, which is **completely outside** the intended media folder at `/tmp/tinacms-test/public/uploads`.\n\n### Important Note: HTTP Layer vs Code Vulnerability\n\nI want to be transparent about my findings:\n\n**What I observed:**\n- When testing via HTTP requests against the Vite dev server, path traversal sequences (`../`) are normalized by Node.js/Vite's HTTP layer *before* reaching the vulnerable code\n- This means direct HTTP exploitation like `curl POST /media/upload/../../../tmp/evil.txt` is mitigated in the default configuration\n\n**Why this is still a valid vulnerability that should be fixed:**\n\n1. **The code itself has no validation** - If the path reaches the handler (via any vector), it will be exploited\n2. **Defense-in-depth principle** - Security should not rely solely on HTTP normalization\n3. **Inconsistent protection** - Your GraphQL layer (`addPendingDocument`) explicitly validates paths and rejects `../` (see test at `packages/@tinacms/graphql/tests/pending-document-validation/index.test.ts:59`), but the media endpoints don't have equivalent protection\n4. **Different deployment contexts**:\n   - Reverse proxies (nginx, Apache) with `proxy_pass` may preserve raw paths\n   - Custom server configurations\n   - Future refactoring that uses this code differently\n5. **The `parseMediaFolder` helper** (line 66-74) shows intent to restrict paths - the upload handler should have similar restrictions\n6. **Express version also affected** - `packages/@tinacms/cli/src/server/routes/index.ts` has the same pattern\n\n---\n\n### Evidence That Path Traversal Should Be Blocked\n\nYour codebase already shows that path traversal is considered a security issue:\n\n```typescript\n// From: packages/@tinacms/graphql/tests/pending-document-validation/index.test.ts:52-70\nit('handles validation error for invalid path format', async () =\u003e {\n  const { query } = await setupMutation(__dirname, config);\n\n  const invalidPathMutation = `\n    mutation {\n      addPendingDocument(\n        collection: \"post\"\n        relativePath: \"../invalid-path.md\"  // \u003c-- Path traversal is rejected!\n      ) {\n        __typename\n      }\n    }\n  `;\n\n  const result = await query({ query: invalidPathMutation, variables: {} });\n\n  expect(result.errors).toBeDefined();\n  expect(result.errors?.length).toBeGreaterThan(0);\n});\n```\n\nThis test explicitly verifies that `../invalid-path.md` is rejected in the GraphQL layer. The media upload endpoints should have the same protection.\n\n---\n\n## Impact\n\n### Who is Affected\n\n- Developers running TinaCMS in development mode\n- Any deployment exposing the TinaCMS dev server API\n- Particularly concerning if dev servers are exposed to networks (common for mobile testing)\n\n### Potential Attack Scenarios\n\n1. **Remote Code Execution**: Write malicious files to executable locations\n   - Overwrite `~/.ssh/authorized_keys` for SSH access\n   - Modify application source code\n   - Create cron jobs or systemd services\n\n2. **Denial of Service**: Delete critical application or system files\n\n3. **Information Disclosure**: List directory contents outside the media folder\n\n### CVSS Score Estimate\n\n**CVSS 3.1 Base Score: 8.1 (High)**\n- Attack Vector: Network (AV:N)\n- Attack Complexity: Low (AC:L)  \n- Privileges Required: None (PR:N)\n- User Interaction: None (UI:N)\n- Scope: Unchanged (S:U)\n- Confidentiality: None (C:N)\n- Integrity: High (I:H)\n- Availability: High (A:H)\n\n---\n\n## Recommended Fix\n\nAdd path validation to ensure the resolved path stays within the media directory:\n\n```typescript\nimport path from 'path';\n\nconst handlePost = async function (req, res) {\n  const bb = busboy({ headers: req.headers });\n\n  bb.on('file', async (_name, file, _info) =\u003e {\n    const fullPath = decodeURI(req.url?.slice('/media/upload/'.length));\n    const saveTo = path.join(mediaFolder, ...fullPath.split('/'));\n\n    // ✅ SECURITY FIX: Validate path stays within media folder\n    const resolvedPath = path.resolve(saveTo);\n    const resolvedMediaFolder = path.resolve(mediaFolder);\n\n    if (!resolvedPath.startsWith(resolvedMediaFolder + path.sep)) {\n      res.statusCode = 403;\n      res.end(JSON.stringify({ error: 'Invalid file path' }));\n      return;\n    }\n\n    await fs.ensureDir(path.dirname(saveTo));\n    file.pipe(fs.createWriteStream(saveTo));\n  });\n  \n  // ... rest of handler\n};\n```\n\nThe same fix should be applied to:\n- `handleDelete` function\n- `handleList` function  \n- `MediaModel.listMedia` method\n- `MediaModel.deleteMedia` method\n- Express router in `packages/@tinacms/cli/src/server/`\n\n### Alternative: Create a Validation Helper\n\n```typescript\nfunction validateMediaPath(userPath: string, mediaFolder: string): string {\n  const resolved = path.resolve(path.join(mediaFolder, ...userPath.split('/')));\n  const resolvedBase = path.resolve(mediaFolder);\n  \n  if (!resolved.startsWith(resolvedBase + path.sep) \u0026\u0026 resolved !== resolvedBase) {\n    throw new Error('Path traversal detected');\n  }\n  \n  return resolved;\n}\n```\n\n---\n\n## References\n\n- [CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')](https://cwe.mitre.org/data/definitions/22.html)\n- [OWASP Path Traversal](https://owasp.org/www-community/attacks/Path_Traversal)\n- [Node.js path.join() Documentation](https://nodejs.org/api/path.html#pathjoinpaths)\n- [OWASP Testing Guide - Path Traversal](https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/05-Authorization_Testing/01-Testing_Directory_Traversal_File_Include)","status":"published","published":"2026-03-12T18:32:38Z","modified":"2026-03-12T18:32:38Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:39:35.644357Z"}],"nvd":[{"id":"CVE-2026-28791","description":"Tina is a headless content management system. Prior to 2.1.7, a path traversal vulnerability exists in the TinaCMS development server's media upload handler. The code at media.ts joins user-controlled path segments using path.join() without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem. This vulnerability is fixed in 2.1.7.","status":"published","published":"2026-03-12T17:16:50.237Z","modified":"2026-06-17T10:29:03.097Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:09.358914Z"}],"osv":[{"id":"CVE-2026-28791","title":"Path Traversal in Media Upload Handle in Tina","description":"Tina is a headless content management system. Prior to 2.1.7, a path traversal vulnerability exists in the TinaCMS development server's media upload handler. The code at media.ts joins user-controlled path segments using path.join() without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem. This vulnerability is fixed in 2.1.7.","status":"published","published":"2026-03-12T16:55:47.528Z","modified":"2026-10-28T02:31:01.564959625Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:00.530889Z"},{"id":"GHSA-5hxf-c7j4-279c","title":"Tina: Path Traversal in Media Upload Handle","description":"## Affected Package\n\n| Field | Value |\n|-------|-------|\n| **Package** | `@tinacms/cli` |\n| **Version** | `2.0.5` (latest at time of discovery) |\n| **Vulnerable File** | `packages/@tinacms/cli/src/next/commands/dev-command/server/media.ts` |\n| **Vulnerable Lines** | 42-43 |\n\n---\n\n## Summary\n\nA **path traversal vulnerability (CWE-22)** exists in the TinaCMS development server's media upload handler. The code at `media.ts:42-43` joins user-controlled path segments using `path.join()` without validating that the resulting path stays within the intended media directory. This allows writing files to arbitrary locations on the filesystem.\n\n**Attack Vector**: Network (HTTP POST request)  \n**Impact**: Arbitrary file write, potential Remote Code Execution\n\n---\n\n## Details\n\n### Vulnerable Code Location\n\n**File**: `packages/@tinacms/cli/src/next/commands/dev-command/server/media.ts`  \n**Lines**: 42-43\n\n```typescript\nbb.on('file', async (_name, file, _info) =\u003e {\n  const fullPath = decodeURI(req.url?.slice('/media/upload/'.length));  // Line 42\n  const saveTo = path.join(mediaFolder, ...fullPath.split('/'));        // Line 43\n  // make sure the directory exists before writing the file\n  await fs.ensureDir(path.dirname(saveTo));\n  file.pipe(fs.createWriteStream(saveTo));\n});\n```\n\n### Root Cause\n\nThe `path.join()` function resolves `..` (parent directory) segments in the path. When the user-supplied path contains traversal sequences like `../../../etc/passwd`, these are resolved relative to the media folder, allowing escape to arbitrary filesystem locations.\n\n**Example**:\n```javascript\nconst mediaFolder = '/app/public/uploads';\nconst maliciousInput = '../../../tmp/evil.txt';\nconst saveTo = path.join(mediaFolder, ...maliciousInput.split('/'));\n// Result: '/tmp/evil.txt' - OUTSIDE the media folder!\n```\n\n### Additional Affected Endpoints\n\nThe same vulnerability pattern exists in:\n\n1. **Delete Handler** (`handleDelete`, lines 29-33) - Arbitrary file deletion\n2. **List Handler** (`handleList`, lines 16-27) + `MediaModel.listMedia` - Directory enumeration\n3. **MediaModel.deleteMedia** (lines 201-217) - Arbitrary file deletion\n\nSimilar code also exists in the Express version at:\n- `packages/@tinacms/cli/src/server/routes/index.ts`\n- `packages/@tinacms/cli/src/server/models/media.ts`\n\n---\n\n## PoC\n\n### Quick Verification (No Server Required)\n\nThis Node.js script directly tests the vulnerable code logic:\n\n```javascript\n#!/usr/bin/env node\n/**\n * TinaCMS Path Traversal Vulnerability - Direct Code Test\n * Run: node test-vulnerability.js\n */\n\nconst path = require('path');\nconst fs = require('fs');\n\n// Simulated configuration (matches typical TinaCMS setup)\nconst rootPath = '/tmp/tinacms-test';\nconst publicFolder = 'public';\nconst mediaRoot = 'uploads';\nconst mediaFolder = path.join(rootPath, publicFolder, mediaRoot);\n\n// Setup test directories\nfs.mkdirSync(path.join(rootPath, publicFolder, mediaRoot), { recursive: true });\nfs.mkdirSync('/tmp/target-dir', { recursive: true });\n\nconsole.log(`Media folder: ${mediaFolder}`);\n\n// Simulate vulnerable code from media.ts:42-43\nfunction vulnerableUpload(reqUrl) {\n    const fullPath = decodeURI(reqUrl.slice('/media/upload/'.length));\n    const saveTo = path.join(mediaFolder, ...fullPath.split('/'));\n    return saveTo;\n}\n\n// Test cases\nconst tests = [\n    { url: '/media/upload/image.png', desc: 'Normal upload' },\n    { url: '/media/upload/../../../tmp/target-dir/evil.txt', desc: 'Path traversal' },\n];\n\ntests.forEach(test =\u003e {\n    const result = vulnerableUpload(test.url);\n    const isVuln = !path.resolve(result).startsWith(path.resolve(mediaFolder));\n    \n    console.log(`\\n${test.desc}:`);\n    console.log(`  Input: ${test.url}`);\n    console.log(`  Result: ${result}`);\n    console.log(`  Vulnerable: ${isVuln ? 'YES ⚠️' : 'No ✓'}`);\n    \n    if (isVuln) {\n        // Actually write the file to prove it works\n        fs.mkdirSync(path.dirname(result), { recursive: true });\n        fs.writeFileSync(result, `PWNED at ${new Date().toISOString()}`);\n        console.log(`  File written: ${fs.existsSync(result)}`);\n    }\n});\n\n// Cleanup\nfs.rmSync(rootPath, { recursive: true, force: true });\n```\n\n### Output\n\n```\nMedia folder: /tmp/tinacms-test/public/uploads\n\nNormal upload:\n  Input: /media/upload/image.png\n  Result: /tmp/tinacms-test/public/uploads/image.png\n  Vulnerable: No ✓\n\nPath traversal:\n  Input: /media/upload/../../../tmp/target-dir/evil.txt\n  Result: /tmp/tmp/target-dir/evil.txt\n  Vulnerable: YES ⚠️\n  File written: true\n```\n\nThe file was successfully written to `/tmp/tmp/target-dir/evil.txt`, which is **completely outside** the intended media folder at `/tmp/tinacms-test/public/uploads`.\n\n### Important Note: HTTP Layer vs Code Vulnerability\n\nI want to be transparent about my findings:\n\n**What I observed:**\n- When testing via HTTP requests against the Vite dev server, path traversal sequences (`../`) are normalized by Node.js/Vite's HTTP layer *before* reaching the vulnerable code\n- This means direct HTTP exploitation like `curl POST /media/upload/../../../tmp/evil.txt` is mitigated in the default configuration\n\n**Why this is still a valid vulnerability that should be fixed:**\n\n1. **The code itself has no validation** - If the path reaches the handler (via any vector), it will be exploited\n2. **Defense-in-depth principle** - Security should not rely solely on HTTP normalization\n3. **Inconsistent protection** - Your GraphQL layer (`addPendingDocument`) explicitly validates paths and rejects `../` (see test at `packages/@tinacms/graphql/tests/pending-document-validation/index.test.ts:59`), but the media endpoints don't have equivalent protection\n4. **Different deployment contexts**:\n   - Reverse proxies (nginx, Apache) with `proxy_pass` may preserve raw paths\n   - Custom server configurations\n   - Future refactoring that uses this code differently\n5. **The `parseMediaFolder` helper** (line 66-74) shows intent to restrict paths - the upload handler should have similar restrictions\n6. **Express version also affected** - `packages/@tinacms/cli/src/server/routes/index.ts` has the same pattern\n\n---\n\n### Evidence That Path Traversal Should Be Blocked\n\nYour codebase already shows that path traversal is considered a security issue:\n\n```typescript\n// From: packages/@tinacms/graphql/tests/pending-document-validation/index.test.ts:52-70\nit('handles validation error for invalid path format', async () =\u003e {\n  const { query } = await setupMutation(__dirname, config);\n\n  const invalidPathMutation = `\n    mutation {\n      addPendingDocument(\n        collection: \"post\"\n        relativePath: \"../invalid-path.md\"  // \u003c-- Path traversal is rejected!\n      ) {\n        __typename\n      }\n    }\n  `;\n\n  const result = await query({ query: invalidPathMutation, variables: {} });\n\n  expect(result.errors).toBeDefined();\n  expect(result.errors?.length).toBeGreaterThan(0);\n});\n```\n\nThis test explicitly verifies that `../invalid-path.md` is rejected in the GraphQL layer. The media upload endpoints should have the same protection.\n\n---\n\n## Impact\n\n### Who is Affected\n\n- Developers running TinaCMS in development mode\n- Any deployment exposing the TinaCMS dev server API\n- Particularly concerning if dev servers are exposed to networks (common for mobile testing)\n\n### Potential Attack Scenarios\n\n1. **Remote Code Execution**: Write malicious files to executable locations\n   - Overwrite `~/.ssh/authorized_keys` for SSH access\n   - Modify application source code\n   - Create cron jobs or systemd services\n\n2. **Denial of Service**: Delete critical application or system files\n\n3. **Information Disclosure**: List directory contents outside the media folder\n\n### CVSS Score Estimate\n\n**CVSS 3.1 Base Score: 8.1 (High)**\n- Attack Vector: Network (AV:N)\n- Attack Complexity: Low (AC:L)  \n- Privileges Required: None (PR:N)\n- User Interaction: None (UI:N)\n- Scope: Unchanged (S:U)\n- Confidentiality: None (C:N)\n- Integrity: High (I:H)\n- Availability: High (A:H)\n\n---\n\n## Recommended Fix\n\nAdd path validation to ensure the resolved path stays within the media directory:\n\n```typescript\nimport path from 'path';\n\nconst handlePost = async function (req, res) {\n  const bb = busboy({ headers: req.headers });\n\n  bb.on('file', async (_name, file, _info) =\u003e {\n    const fullPath = decodeURI(req.url?.slice('/media/upload/'.length));\n    const saveTo = path.join(mediaFolder, ...fullPath.split('/'));\n\n    // ✅ SECURITY FIX: Validate path stays within media folder\n    const resolvedPath = path.resolve(saveTo);\n    const resolvedMediaFolder = path.resolve(mediaFolder);\n\n    if (!resolvedPath.startsWith(resolvedMediaFolder + path.sep)) {\n      res.statusCode = 403;\n      res.end(JSON.stringify({ error: 'Invalid file path' }));\n      return;\n    }\n\n    await fs.ensureDir(path.dirname(saveTo));\n    file.pipe(fs.createWriteStream(saveTo));\n  });\n  \n  // ... rest of handler\n};\n```\n\nThe same fix should be applied to:\n- `handleDelete` function\n- `handleList` function  \n- `MediaModel.listMedia` method\n- `MediaModel.deleteMedia` method\n- Express router in `packages/@tinacms/cli/src/server/`\n\n### Alternative: Create a Validation Helper\n\n```typescript\nfunction validateMediaPath(userPath: string, mediaFolder: string): string {\n  const resolved = path.resolve(path.join(mediaFolder, ...userPath.split('/')));\n  const resolvedBase = path.resolve(mediaFolder);\n  \n  if (!resolved.startsWith(resolvedBase + path.sep) \u0026\u0026 resolved !== resolvedBase) {\n    throw new Error('Path traversal detected');\n  }\n  \n  return resolved;\n}\n```\n\n---\n\n## References\n\n- [CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')](https://cwe.mitre.org/data/definitions/22.html)\n- [OWASP Path Traversal](https://owasp.org/www-community/attacks/Path_Traversal)\n- [Node.js path.join() Documentation](https://nodejs.org/api/path.html#pathjoinpaths)\n- [OWASP Testing Guide - Path Traversal](https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/05-Authorization_Testing/01-Testing_Directory_Traversal_File_Include)","status":"published","published":"2026-03-12T18:32:38Z","modified":"2026-03-14T05:56:20.74271Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:38.553953Z"}]}}