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.
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History
Fri, 29 May 2026 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | FreeScout: Agent Impersonation via Missing HMAC Verification on Notification Reply Message-ID Path | |
| Weaknesses | CWE-290 CWE-345 |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-29T19:51:41.383Z
Reserved: 2026-05-18T19:50:18.694Z
Link: CVE-2026-47123
No data.
Status : Deferred
Published: 2026-05-29T20:16:28.380
Modified: 2026-05-29T20:21:38.773
Link: CVE-2026-47123
No data.
OpenCVE Enrichment
No data.