FreeScout's deserialization of untrusted data leads to Remote Code Execution
FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2025-54366
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 03:57 UTC · Revision 1
Source evidence
FreeScout's deserialization of untrusted data leads to Remote Code Execution
core-osv · Original sourcePublished 26 Jul 2025, 03:35 UTC
FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.
osv:CVE-2025-54366
Complete source record
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"title": "FreeScout's deserialization of untrusted data leads to Remote Code Execution",
"summary": "FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.",
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"modified": "2026-10-28T02:30:25.911768200Z",
"provider": "osv",
"references": [
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"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-vcc2-6r66-gvvj",
"https://nvd.nist.gov/vuln/detail/CVE-2025-54366",
"https://github.com/freescout-help-desk/freescout/commit/9669c57f1ddbee896752d9e16270abfd97b20eb9"
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"evidence": "/id"
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"source_id": "core-osv",
"document_id": 492313,
"published_at": "2025-07-26T03:35:17.444+00:00"
}