CVE-2026-34824

HIGH

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

Title source: cna

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.

Scores

CVSS v3 7.5
EPSS 0.0003
EPSS Percentile 7.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-125 CWE-770
Status published
Products (3)
mesop-dev/mesop 1.2.3 - 1.2.5
mesop-dev/mesop >= 1.2.3, < 1.2.5
pypi/mesop 1.2.3 - 1.2.5PyPI
Published Apr 03, 2026
Tracked Since Apr 04, 2026