---
id: "CVE-2026-62854"
page: "https://infrastack.ai/live/CVE-2026-62854"
kind: "vulnerability"
aliases: ["CVE-2026-62854"]
title: "FreeScout: mailbox signature XSS lets attacker run scripts in other users' sessions"
severity: "high"
cvss: 7.6
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["freescout", "helpdesk", "package", "self-hosted"]
not_affected_if: ["fixed-version-1.8.225", "no-signature-editors"]
published_at: "2026-11-06T17:18:33+00:00"
first_seen_at: "2026-11-06T17:43:14+00:00"
updated_at: "2026-11-06T17:45:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-62854", "first_seen_at": "2026-11-06T17:43:14+00:00"}]
exploit_sources: []
---

# FreeScout: mailbox signature XSS lets attacker run scripts in other users' sessions

Link for people: https://infrastack.ai/live/CVE-2026-62854 (this .md is for agents)

FreeScout, a self-hosted help desk, lets a user who can edit a mailbox signature upload a scriptable file and bypass tag stripping so the file loads as a script. When another user opens the affected mailbox reply editor or new-ticket page, the script runs with that user's FreeScout privileges, reading visible data and acting as them.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the FreeScout version in the installed application; versions below `1.8.225` are affected.
- Review who can edit mailbox signatures in the admin settings.
- Look for unexpected uploaded script-like files under the uploads directory.

## Fix

- FreeScout: upgrade to `1.8.225`.

## Timeline

- 2026-11-06T17:43:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-62854

## Documents

- [advisory] Vendor advisory: github.com https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98
- [fix] Patch: github.com https://github.com/freescout-help-desk/freescout/commit/315ad05f73886649cb8bc2c014dd74b62cc28502
- [fix] Patch: github.com https://github.com/freescout-help-desk/freescout/commit/7f6a5042c1326ceaf511f13982178dce036cedbe
- [fix] Release notes: github.com https://github.com/freescout-help-desk/freescout/releases/tag/1.8.225

## From the sources

FreeScout is a self-hosted help desk and shared mailbox. Prior to 1.8.225, a user who can edit a mailbox signature can combine a scriptable file uploaded through /uploads/upload with nested tag fragments that bypass Helper::stripDangerousTags(). The resulting external script is served from the same origin, so the script-src 'self' policy permits it when another user opens the affected mailbox reply editor or new-ticket page. The script executes with the victim's FreeScout privileges and can read visible data and perform same-origin actions. This issue is fixed in version 1.8.225.

---

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