CVE-2026-40497

April 21, 2026, 4:20 p.m.

8.1
High

Description

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.

Product(s) Impacted

Vendor Product Versions
Freescout
  • Freescout
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-79
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

CVSS Score

8.1 / 10

CVSS Data - 3.1

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Privileges Required: HIGH
  • Scope: CHANGED
  • Confidentiality Impact: HIGH
  • Integrity Impact: HIGH
  • Availability Impact: NONE
  • CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

    View Vector String

Timeline

Published: April 21, 2026, 3:16 a.m.
Last Modified: April 21, 2026, 4:20 p.m.

Status : Undergoing Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.