High 7.5Published Apr 3, 2026

CVE-2026-34824Mesop: Unbounded Thread Creation in WebSocket Handler Leads to Denial of Service

Updated under an hour ago (Oct 26, 2026, 3:50 PM ET)

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Every CVE for mesop-dev mesop

Exploited in the last 30 days

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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-125
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Apr 6, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mesop-dev mesop mesop_dev:mesop (from the name)	from 1.2.3, < 1.2.5	CNA record
mesop-dev mesop mesop-dev:mesop	from 1.2.3 before 1.2.5	NVD

References

References

https://github.com/mesop-dev/mesop/security/advisories/GHSA-3jr7-6hqp-x679	x-refsource-confirm, exploit, mitigation, vendor-advisory
https://github.com/mesop-dev/mesop/commit/760a2079b5c609038c826d24dfbcf9b0be98d987	x-refsource-misc, patch
https://github.com/mesop-dev/mesop/releases/tag/v1.2.5	x-refsource-misc, product, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.