PT-2026-61701 · Freescout Help Desk · Freescout
CVE-2026-53591
·
Published
2026-07-20
·
Updated
2026-07-20
CVSS v3.1
8.6
High
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L |
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.Exploit
Fix
Improper Authentication
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Weakness Enumeration
Related Identifiers
Affected Products
Freescout