What is the CVSS score of EUVD-2026-46081?

EUVD-2026-46081 has a CVSS 3.1 base score of 8.6 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L. EPSS exploitation probability: 0.2%.

Which versions of FreeScout are affected by EUVD-2026-46081?

FreeScout self-hosted help desk (versions prior to 1.8.223) is vulnerable to unauthenticated message injection allowing attackers to forge customer replies in support conversations without…. A patch is available.

How to fix or mitigate EUVD-2026-46081?

Within 24 hours, audit support conversations from the past 30 days for anomalous customer replies and implement email gateway filtering to block messages with forged In-Reply-To headers. Within 7 days, enable enhanced logging on message ingestion in FreeScout, require agent verification before responding to reopened conversations, and evaluate isolating the help desk from external email if operationally feasible. Within 30 days, monitor FreeScout release notes for a patch to version 1.8.223 or later, evaluate emergency vendor support, enforce DKIM/SPF at the mail gateway, and implement customer identity verification workflows for ticket state changes.

FreeScout EUVD-2026-46081

| CVE-2026-53591 HIGH

Improper Authentication (CWE-287)

2026-07-20 GitHub_M

Authentication Bypass Freescout

8.6

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

8.6 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

vuln.today AI

7.5 HIGH

Single unauthenticated email exploits it remotely (AV:N/AC:L/PR:N/UI:N); impact is pure integrity via spoofed replies (I:H), with no genuine data disclosure or outage (C:N/A:N).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

Low

Lifecycle Timeline

Patch available

Jul 20, 2026 - 21:17 EUVD

Analysis Generated

Jul 20, 2026 - 20:19 vuln.today

CVE Published

Jul 20, 2026 - 19:47 cve.org

HIGH 8.6

DescriptionCVE.org

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.

AnalysisAI

Message injection in FreeScout self-hosted help desk (all versions prior to 1.8.223) lets a remote unauthenticated attacker forge customer replies inside any existing support conversation. By emailing the helpdesk's public intake address with a crafted In-Reply-To header that references a target thread, the attacker's message renders in the agent UI as a legitimate customer reply, silently reopens the conversation, and overwrites last_reply_from with the attacker's identity. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Craft email with forged In-Reply-To header

Delivery

Send to public helpdesk address

Exploit

Bypass sender verification (CWE-287)

Execution

Message grafted into target conversation

Persist

Agent UI renders spoofed customer reply

Impact

Social-engineer agent action