Vulnerabilities

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can access diagnostic and system tools that should be restricted to administrators. The /system/cron endpoint relies on a static MD5 hash derived from the APP_KEY, which is exposed in the response and logs. Accessing these endpoints reveals sensitive server information (Full Path Disclosure), process IDs, and allows for Resource Exhaustion (DoS) by triggering heavy background tasks repeatedly without any rate limiting. The cron hash is generated using md5(APP_KEY . 'web_cron_hash'). Since this hash is often transmitted via GET requests, it is susceptible to exposure in server logs, browser history, and proxy logs. Furthermore, the lack of rate limiting on these endpoints allows for automated resource exhaustion (DoS) and brute-force attempts. Version 1.8.213 fixes the issue.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.212, FreeScout does not take the limit_user_customer_visibility parameter into account when merging customers. This vulnerability is fixed in 1.8.212.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.211, checkIpByMask() in app/Misc/Helper.php checks whether the input IP contains a / character. Plain IP addresses never contain /, so the function always returns false without checking any CIDR ranges. The entire 10.0.0.0/8 and 172.16.0.0/12 private ranges are unprotected. This issue has been patched in version 1.8.211.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Versions 1.8.208 and below are vulnerable to Stored Cross-Site Scripting (XSS) through FreeScout's email notification templates. Incoming email bodies are stored in the database without sanitization and rendered unescaped in outgoing email notifications using Blade's raw output syntax {!! $thread->body !!}. An unauthenticated attacker can exploit this vulnerability by simply sending an email, and when opened by any subscribed agent or admin as part of their normal workflow, enabling universal HTML injection (phishing, tracking) and, in vulnerable email clients, JavaScript execution (session hijacking, credential theft, account takeover) affecting all recipients simultaneously. This issue has been fixed in version 1.8.209.

CVE-2026-28289 is a patch-bypass flaw in FreeScout, a self-hosted PHP/Laravel help desk and shared inbox, that reintroduces the remote code execution previously fixed under CVE-2026-27636. The bug is a time-of-check to time-of-use (TOCTOU) issue in the sanitizeUploadedFileName() function in app/Http/Helper.php: the check for a dot-prefixed filename runs before sanitization strips invisible characters, so a filename beginning with a zero-width space followed by .htaccess passes the security check and is stored as a functional .htaccess file in the upload directory. Any authenticated user with file-upload permissions can exploit this by uploading such a crafted .htaccess file, overriding Apache configuration for the upload path and achieving remote code execution on the server; related reporting also describes an unauthenticated, zero-click vector via emailed attachments. All FreeScout deployments running version 1.8.206 or earlier are affected, and the flaw is fixed in 1.8.207. Exploitation status: public proof-of-concept material and analysis are available (EPSS ~31%, 98th percentile), it is not yet in CISA's KEV catalog, and active in-the-wild exploitation has not been explicitly confirmed in the provided data.

Do: Upgrade FreeScout to version 1.8.207 or later. As interim mitigation, restrict file-upload permissions to trusted users, disallow or ignore .htaccess overrides in upload directories (e.g., Apache AllowOverride None), and audit existing upload directories for .htaccess files or filenames containing zero-width/invisible characters.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.206, FreeScout's `TokenAuth` middleware uses a predictable authentication token computed as `MD5(user_id + created_at + APP_KEY)`. This token is static (never expires/rotates), and if an attacker obtains the `APP_KEY` — a well-documented and common exposure vector in Laravel applications — they can compute a valid token for any user, including the administrator, achieving full account takeover without any password. This vulnerability can be exploited on its own or in combination with CVE-2026-27636. Version 1.8.206 fixes both vulnerabilities.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Versions 1.8.185 and earlier contain a deserialization of untrusted data vulnerability that allows authenticated attackers with knowledge of the application's APP_KEY to achieve remote code execution. The vulnerability is exploited via endpoint, e.g.: `/help/{mailbox_id}/auth/{customer_id}/{hash}/{timestamp}` where the `customer_id` and `timestamp` parameters are processed through the decrypt function in `app/Helper.php` without proper validation. The code decrypts using Laravel's built-in encryption functions, which subsequently deserialize the decrypted payload without sanitization, allowing attackers to craft malicious serialized PHP objects using classes to trigger arbitrary command execution. This is fixed in version 1.8.186.

FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.180, the laravel-translation-manager package does not correctly validate user input, enabling the deletion of any directory, given sufficient access rights. This issue has been patched in version 1.8.180.

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.178, FreeScout is vulnerable to deserialization of untrusted data due to insufficient validation. Through the set function, a string with a serialized object can be passed, and when getting an option through the get method, deserialization will occur, which will allow arbitrary code execution This issue has been patched in version 1.8.178.

FreeScout is a free, self-hosted help desk and shared mailbox. Versions of FreeScout prior to 1.8.139 contain a Prototype Pollution vulnerability in the `/public/js/main.js` source file. The Prototype Pollution arises because the `getQueryParam` Function recursively merges an object containing user-controllable properties into an existing object (For URL Query Parameters Parsing), without first sanitizing the keys. This can allow an attacker to inject a property with a key `__proto__`, along with arbitrarily nested properties. The merge operation assigns the nested properties to the `params` object's prototype instead of the target object itself. As a result, the attacker can pollute the prototype with properties containing harmful values, which are then inherited by user-defined objects and subsequently used by the application dangerously. The vulnerability lets an attacker control properties of objects that would otherwise be inaccessible. If the application subsequently handles an attacker-controlled property in an unsafe way, this can potentially be chained with other vulnerabilities like DOM-based XSS, Open Redirection, Cookie Manipulation, Link Manipulation, HTML Injection, etc. Version 1.8.139 contains a patch for the issue.

FreeScout is a self-hosted help desk and shared mailbox. Versions prior to 1.8.128 are vulnerable to OS Command Injection in the /public/tools.php source file. The value of the php_path parameter is being executed as an OS command by the shell_exec function, without validating it. This allows an adversary to execute malicious OS commands on the server. A practical demonstration of the successful command injection attack extracted the /etc/passwd file of the server. This represented the complete compromise of the server hosting the FreeScout application. This attack requires an attacker to know the `App_Key` of the application. This limitation makes the Attack Complexity to be High. If an attacker gets hold of the `App_Key`, the attacker can compromise the Complete server on which the application is deployed. Version 1.8.128 contains a patch for this issue.

FreeScout is an open source help desk and shared inbox built with PHP. A vulnerability has been identified in the Free Scout Application, which exposes SMTP server credentials used by an organization in the application to users of the application. This issue arises from the application storing complete stack traces of exceptions in its database. The sensitive information is then inadvertently disclosed to users via the `/conversation/ajax-html/send_log?folder_id=&thread_id={id}` endpoint. The stack trace reveals value of parameters, including the username and password, passed to the `Swift_Transport_Esmtp_Auth_LoginAuthenticator->authenticate()` function. Exploiting this vulnerability allows an attacker to gain unauthorized access to SMTP server credentials. With this sensitive information in hand, the attacker can potentially send unauthorized emails from the compromised SMTP server, posing a severe threat to the confidentiality and integrity of email communications. This could lead to targeted attacks on both the application users and the organization itself, compromising the security of email exchange servers. This issue has been addressed in version 1.8.124. Users are advised to upgrade. Users unable to upgrade should adopt the following measures: 1. Avoid Storing Complete Stack Traces, 2. Implement redaction mechanisms to filter and exclude sensitive information, and 3. Review and enhance the application's logging practices.

Unrestricted Upload of File with Dangerous Type in freescout-helpdesk/freescout