CVE-2026-40565 FreeScout has Stored XSS / CSS Injection via linkify() — Unescaped URL in Anchor href
Attackers can inject malicious scripts via unescaped URLs in email bodies, potentially leading to session hijacking or code execution in FreeScout.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-40565?
CVE-2026-40565 is a medium-severity cross-site scripting vulnerability in freescout-help-desk freescout, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, FreeScout's linkify() function in app/Misc/Helper.php converts plain-text URLs in email bodies into HTML anchor tags without escaping double-quote characters (") in the URL. HTMLPurifier (called first via getCleanBody()) preserves literal " characters in text nodes. linkify() then wraps URLs including those " chars inside an unescaped href="..." attribute, breaking out of the href and injecting arbitrary HTML attributes. Version 1.8.213 fixes the issue.
Weakness: CWE-79
Which versions are affected by CVE-2026-40565?
It affects 1 product.
Products include Freescout Freescout.
How do I fix CVE-2026-40565?
No fix has been published for CVE-2026-40565 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-40565 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40565 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-2026-40498 FreeScout has Authentication Bypass and Information Disclosure in SystemController via /system/cron
Sources
Also known as GHSA-49pm-xwqj-vwjp.