CVE-2026-40497

What it is

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, FreeScout's `Helper::stripDangerousTags()` removes `<script>`, `<form>`, `<iframe>`, `<object>` but does NOT strip `<style>` tags. The mailbox signature field is saved via POST /mailbox/settings/{id} and later rendered unescaped via `{!! $conversation->getSignatureProcessed([], true) !!}` in conversation views. CSP allows `style-src * 'self' 'unsafe-inline'`, so injected inline styles execute freely. An attacker with access to mailbox settings (admin or agent with mailbox permission) can inject CSS attribute selectors to exfiltrate the CSRF token of any agent/admin who views a conversation in that mailbox. With the CSRF token, the attacker can perform any state-changing action as the victim (create admin accounts, change email/password, etc.) — privilege escalation from agent to admin. This is the result of an incomplete fix of GHSA-jqjf-f566-485j. That advisory reported XSS via mailbox signature. The fix applied `Helper::stripDangerousTags()` to the signature before saving. However, `stripDangerousTags()` only removes `script`, `form`, `iframe`, and `object` tags — it does NOT strip `<style>` tags, leaving CSS injection possible. Version 1.8.213 contains an updated fix.

At a glance

Exploitability

Can be exploited over the network with an admin-level account, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-04-21 03:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:45 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 8.1 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-04-21 03:16 UTC

Last modified

2026-06-17 10:45 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Analyzed

Affected

• Freescout < 1.8.213

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

Low

Privileges needed

High

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-40497.md and follow it. Check whether this project is affected by CVE-2026-40497. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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