TI-2026-27068 Aliases CVE-2026-34824 GHSA-3jr7-6hqp-x679

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

HIGH 72CWE-125Published 2026-04-03 · Updated 2026-04-06

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-125 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.0075 55th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed mesop (mesop-dev): 1.2.5mesop (PyPI): 1.2.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
mesop-dev	mesop	1.2.3 to before 1.2.5	1.2.5	Patch available	CNA
—	mesop (PyPI)	1.2.3 to before 1.2.5	1.2.5	Patch available	GHSA-3jr7-6hqp-x679

mesop Vendormesop-dev Affected 1.2.3 to before 1.2.5 Fixed in 1.2.5 Patch available CNA
mesop (PyPI) Vendor— Affected 1.2.3 to before 1.2.5 Fixed in 1.2.5 Patch available GHSA-3jr7-6hqp-x679

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:mesop-dev:mesop::::::python::*	1.2.3 to before 1.2.5	Vulnerable	mesop-dev

cpe:2.3:a:mesop-dev:mesop:*:*:*:*:*:python:*:* Versions 1.2.3 to before 1.2.5 Vulnerable ·mesop-dev

Remediation

Fix · CNA mesop (mesop-dev) Fixed in 1.2.5
Fix · GHSA-3jr7-6hqp-x679 mesop (PyPI) Fixed in 1.2.5 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-34824
2026-10-03 Alias added: GHSA-3jr7-6hqp-x679

References

Other 2

TI-2026-25500 Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py CVSS 3.1CRITICAL 9.8
TI-2026-25497 Mesop: Path Traversal utilizing `FileStateSessionBackend` leads to Application Denial of Service and File Write/Deletion CVSS 3.1CRITICAL 10.0

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences