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TI-2026-34715 Aliases CVE-2026-47123

FreeScout: Agent Impersonation via Missing HMAC Verification on Notification Reply Message-ID Path

Priority HIGH 66CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-290.

Summary

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.220, the email processing pipeline in FreeScout's FetchEmails command has two code paths for identifying agent (user) replies based on In-Reply-To / References headers. The notification reply path (notify-{thread_id}-{user_id}-...) extracts thread_id and user_id directly from the Message-ID without HMAC verification. An external attacker who can spoof the From address of a helpdesk agent can inject messages that FreeScout processes as legitimate agent replies — which are then automatically forwarded to customers via the legitimate SMTP server. This vulnerability is fixed in 1.8.220.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00145 3rd percentileScored 2026-11-07
Fix Fixed freescout (freescout-help-desk): 1.8.220

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

VendorProductAffected versionsFixed inStatusSource
freescout-help-deskfreescoutbefore 1.8.2201.8.220Patch availableCNA
  • freescout Vendorfreescout-help-desk Affected before 1.8.220 Fixed in 1.8.220 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:freescout:freescout:*:*:*:*:*:*:*:*——freescout-help-desk

Remediation

  • Fix · CNA freescout (freescout-help-desk) Fixed in 1.8.220

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-47123

References

Other 2

  • TI-2026-38652 FreeScout vulnerable to anonymous account takeover via /user-setup empty invite_hash on MySQL CVSS 3.1CRITICAL 9.4
  • TI-2026-22019 FreeScout's Predictable Authentication Token Enables Account Takeover CVSS 3.1CRITICAL 9.8
  • TI-2026-30304 FreeScout's user invitation hash never expires: permanent unauthenticated account takeover if invite link leaks CVSS 3.1CRITICAL 9.1
  • 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-2026-38648 FreeScout Vulnerable to Unauthenticated Conversation Thread Injection via HMAC Length Bypass in FetchEmails CVSS 3.1HIGH 8.6
See all 90 →

Sources

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