CVE-2026-33054

CRITICAL EPSS 49.0%
Published Mar 20, 20263mo ago · Modified Mar 24, 20263mo ago
9.8 CVSS 3.1
Critical
Find Similar
Published Mar 20, 2026 3mo ago
Last Modified Mar 24, 2026 3mo ago

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.

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
49.0% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-22 Path Traversal Resource Mgmt

Affected Products 1

VendorProductVersionRange
mesop-devmesop* <1.2.3

References 3

  • github.com https://github.com/mesop-dev/mesop/commit/c6b382f363b73ac32c402a2db3aadc7784f66a5b
    Patch
  • github.com https://github.com/mesop-dev/mesop/releases/tag/v1.2.3
    Release Notes
  • github.com https://github.com/mesop-dev/mesop/security/advisories/GHSA-8qvf-mr4w-9x2c
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/mesop-dev/mesop/commit/c6b382f363b73ac32c402a2db3aadc7784f66a5b
    Patch