CVE-2025-54366Public exploitNetwork attack vector

Authenticated code execution via attachment deserialization

Published Jul 26, 2025 · Updated Jul 28, 2025

Unsafe deserialization in FreeScout before 1.8.186 allows remote authenticated users to execute code through crafted attachment parameters. ConversationController::decodeAttachmentsIds passes attachments_all and attachments values to Helper::decrypt, which reconstructs attacker-controlled PHP objects without type validation. Exploitation requires an authorized session and knowledge of the instance APP_KEY and compromises the web application under its server process.

CVSS severity8.6
High
EPSS probability0.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in FreeScout before 1.8.186 allows remote authenticated users to execute code through crafted attachment parameters. ConversationController::decodeAttachmentsIds passes attachments_all and attachments values to Helper::decrypt, which reconstructs attacker-controlled PHP objects without type validation. Exploitation requires an authorized session and knowledge of the instance APP_KEY and compromises the web application under its server process.

The record

CVE
CVE-2025-54366
Published
Jul 26, 2025
Updated
Jul 28, 2025
Vendor
FreeScout
Product
FreeScout
Classifications
CWE-502, CAPEC-586, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 26, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.8.186

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FreeScout · FreeScoutversion=< 1.8.186

Published CVSS scores

8.6GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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