CVE-2026-47123highCWE-290CWE-345

CVE-2026-47123: high-severity vulnerability in freescout-help-desk freescout

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

Published · Updated

Follow this CVE+ Monitor freescout

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

41Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 7.5epss 0.1%
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N
Affected products
freescout-help-desk · freescout
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — freescout-help-desk freescout

In the same product, most dangerous first.

CVE-2026-28289CRITICALFreeScout 1.8.206 Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Remote Code ExecutionEPSS 35.1%CVE-2026-27636HIGHFreeScout: Missing .htaccess in Restricted File Extensions Allows Remote Code Execution on ApacheEPSS 2.2%CVE-2026-53595CRITICALFreeScout vulnerable to anonymous account takeover via /user-setup empty invite_hash on MySQLEPSS 1.9%CVE-2025-48471HIGHFreeScout Vulnerable to Arbitrary File UploadEPSS 1.2%CVE-2025-54366HIGHFreeScout's deserialization of untrusted data leads to Remote Code ExecutionEPSS 1.1%CVE-2025-48389HIGHFreeScout Vulnerable to Deserialization of Untrusted DataEPSS 1.0%