CVE-2026-40498 FreeScout has Authentication Bypass and Information Disclosure in SystemController via /system/cron
Unauthenticated attackers can bypass authentication to access system tools, disclose sensitive server information, and cause denial of service via resource exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-40498?
CVE-2026-40498 is a high-severity authentication bypass vulnerability in freescout-help-desk freescout, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-40498?
It affects 1 product.
Products include Freescout Freescout.
How do I fix CVE-2026-40498?
No fix has been published for CVE-2026-40498 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-40498 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40498 exists.
Other vulnerabilities in freescout-help-desk freescout
- CVE-2026-28289 FreeScout 1.8.206 Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Remote Code Execution
- CVE-2026-27637 FreeScout's Predictable Authentication Token Enables Account Takeover
- CVE-2026-32754 FreeScout: Stored XSS via Unescaped Email Template Rendering ({!! $thread->body !!})
- CVE-2024-29185 FreeScout OS Command Injection vulnerability
- CVE-2026-40496 FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force
Sources
Also known as GHSA-5jw5-q9j7-4rxc.