CVE-2026-53593Public exploitNetwork attack vector

Authenticated remote code execution via unblocked .pht upload

Published Jul 20, 2026 · Updated Jul 20, 2026

Unrestricted file upload in FreeScout before 1.8.224 allows remote authenticated users to execute commands via a crafted .pht file. SecureController@upload preserves the client extension in a web-accessible upload directory, while Helper::$restricted_extensions fails to rename .pht files. Any authenticated agent can exploit Apache deployments using libapache2-mod-php to run commands as the web-server user; nginx with PHP-FPM is not affected.

CVSS severity8.8
High
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in FreeScout before 1.8.224 allows remote authenticated users to execute commands via a crafted .pht file. SecureController@upload preserves the client extension in a web-accessible upload directory, while Helper::$restricted_extensions fails to rename .pht files. Any authenticated agent can exploit Apache deployments using libapache2-mod-php to run commands as the web-server user; nginx with PHP-FPM is not affected.

The record

CVE
CVE-2026-53593
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
FreeScout
Product
FreeScout
Classifications
CWE-434, T1190, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 2026Record 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=< 1.8.224

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FreeScout · FreeScoutversion=< 1.8.224

Published CVSS scores

8.8GitHub, Inc.CVSS: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-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application
T1505.003Web Shell

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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