CVE-2026-53591 Details
Description
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.
A vulnerability in FreeScout prior to version 1.8.223 allows unauthenticated attackers to inject messages into existing support conversations. This is achieved by sending an email to the helpdesk's public address with a manipulated 'In-Reply-To' header. The injected message appears in the agent UI as a genuine customer reply, automatically reopens the conversation, and updates the 'last_reply_from' field with the attacker's identity. The vulnerability exploits a flaw in how the application processes email replies, bypassing necessary authentication checks.
Users can update to FreeScout version 1.8.223 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 20, 2026CISA-ADP
Assessed Jul 20, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| FreeScout | < 1.8.223 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 20, 2026 | CVE Modified | CISA-ADP |
| Jul 20, 2026 | New CVE Received | [email protected] |