CVE-2026-34824

Mesop: Unbounded Thread Creation in WebSocket Handler Leads to Denial of Service

Published Apr 3, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Mesop is a Python-based UI framework that allows users to build web applications. From version 1.2.3 to before version 1.2.5, an uncontrolled resource consumption vulnerability exists in the WebSocket implementation of the Mesop framework. An unauthenticated attacker can send a rapid succession of WebSocket messages, forcing the server to spawn an unbounded number of operating system threads. This leads to thread exhaustion and Out of Memory (OOM) errors, causing a complete Denial of Service (DoS) for any application built on the framework. This issue has been patched in version 1.2.5.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-3jr7-6hqp-x679 Mesop: Unbounded Thread Creation in WebSocket Handler Leads to Denial of Service
History
Type Values Removed Values Added
Weaknesses CWE-770
CPEs cpe:2.3:a:mesop-dev:mesop:*:*:*:*:*:python:*:*
Type Values Removed Values Added
First Time appeared Mesop-dev
Mesop-dev mesop
Vendors & Products Mesop-dev
Mesop-dev mesop
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description Mesop is a Python-based UI framework that allows users to build web applications. From version 1.2.3 to before version 1.2.5, an uncontrolled resource consumption vulnerability exists in the WebSocket implementation of the Mesop framework. An unauthenticated attacker can send a rapid succession of WebSocket messages, forcing the server to spawn an unbounded number of operating system threads. This leads to thread exhaustion and Out of Memory (OOM) errors, causing a complete Denial of Service (DoS) for any application built on the framework. This issue has been patched in version 1.2.5.
Title Mesop: Unbounded Thread Creation in WebSocket Handler Leads to Denial of Service
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Apr 6, 2026, 3:42 PM
Reserved
Mar 30, 2026, 8:52 PM
Status
Analyzed
Published
Apr 3, 2026, 11:17 PM
Modified
Jul 24, 2026, 10:10 PM