FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.223, an unauthenticated attacker can inject messages into any existing support conversation by sending a single email to the helpdesk's public address with a crafted `In-Reply-To` header. No credentials, tokens, or prior access are required. The injected message is rendered in the agent UI as a legitimate customer reply, the conversation is automatically reopened, and the `last_reply_from` field is set to the attacker's identity. Version 1.8.223 contains a fix.
References
Configurations
No configuration.
History
No history.
Information
Published : 2026-07-20 20:16
Updated : 2026-07-21 19:25
NVD link : CVE-2026-53591
Mitre link : CVE-2026-53591
CVE.ORG link : CVE-2026-53591
JSON object : View
Products Affected
No product.
CWE
CWE-287
Improper Authentication
