cvedb.io
CVE-2026-53591
HIGH · CVSS 8.6
EPSS exploitation probability: 0%
Published 2026-07-20T20:16:44.613 · Last modified 2026-07-20T21:16:48.180

Summary

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.

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.