Mesop is a Python-based UI framework that allows users to build web applications. Versions 1.2.2 and below contain a Path Traversal vulnerability that allows any user supplying an untrusted state_token through the UI stream payload to arbitrarily target files on the disk under the standard file-based runtime backend. This can result in application denial of service (via crash loops when reading non-msgpack target files as configurations), or arbitrary file manipulation. This vulnerability heavily exposes systems hosted utilizing FileStateSessionBackend. Unauthorized malicious actors could interact with arbitrary payloads overwriting or explicitly removing underlying service resources natively outside the application bounds. This issue has been fixed in version 1.2.3.
History

Fri, 20 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 20 Mar 2026 09:00:00 +0000

Type Values Removed Values Added
First Time appeared Mesop-dev
Mesop-dev mesop
Vendors & Products Mesop-dev
Mesop-dev mesop

Fri, 20 Mar 2026 07:15:00 +0000

Type Values Removed Values Added
Description Mesop is a Python-based UI framework that allows users to build web applications. Versions 1.2.2 and below contain a Path Traversal vulnerability that allows any user supplying an untrusted state_token through the UI stream payload to arbitrarily target files on the disk under the standard file-based runtime backend. This can result in application denial of service (via crash loops when reading non-msgpack target files as configurations), or arbitrary file manipulation. This vulnerability heavily exposes systems hosted utilizing FileStateSessionBackend. Unauthorized malicious actors could interact with arbitrary payloads overwriting or explicitly removing underlying service resources natively outside the application bounds. This issue has been fixed in version 1.2.3.
Title Mesop: Path Traversal utilizing `FileStateSessionBackend` leads to Application Denial of Service and File Write/Deletion
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-03-20T06:57:35.948Z

Updated: 2026-03-20T13:50:27.328Z

Reserved: 2026-03-17T18:10:50.212Z

Link: CVE-2026-33054

cve-icon Vulnrichment

Updated: 2026-03-20T13:50:22.516Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-20T07:16:13.363

Modified: 2026-03-20T14:16:15.173

Link: CVE-2026-33054

cve-icon Redhat

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