TI-2026-29306 Aliases CVE-2026-40565

FreeScout has Stored XSS / CSS Injection via linkify() — Unescaped URL in Anchor href

MEDIUM 60CWE-79Published 2026-04-21 · Updated 2026-04-21

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00199 9th percentileScored 2026-11-07

Fix Fixed freescout (freescout-help-desk): 1.8.213

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
freescout-help-desk	freescout	before 1.8.213	1.8.213	Patch available	CNA

freescout Vendorfreescout-help-desk Affected before 1.8.213 Fixed in 1.8.213 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:freescout:freescout::::::::	before 1.8.213	Vulnerable	freescout-help-desk

cpe:2.3:a:freescout:freescout:*:*:*:*:*:*:*:* Versions before 1.8.213 Vulnerable ·freescout-help-desk

Remediation

Fix · CNA freescout (freescout-help-desk) Fixed in 1.8.213

Timeline

2026-10-02 Threatist record created from CVE-2026-40565

References

TI-2026-22019 FreeScout's Predictable Authentication Token Enables Account Takeover CVSS 3.1CRITICAL 9.8
TI-2026-29249 FreeScout has Authentication Bypass and Information Disclosure in SystemController via /system/cron CVSS 4.0HIGH 8.9
TI-2026-29247 FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force CVSS 4.0HIGH 8.8
TI-2026-25245 FreeScout: Stored XSS via Unescaped Email Template Rendering ({!! $thread->body !!}) CVSS 3.1CRITICAL 9.3
TI-2026-22596 FreeScout 1.8.206 Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Remote Code Execution CVSS 3.1CRITICAL 10.0
TI-2024-19354 FreeScout OS Command Injection vulnerability CVSS 3.1CRITICAL 9.1

See all 45 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences