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.
Affected products
mesop-dev: mesop
References4
- github.com/mesop-dev/mesop/security/advisories/GHSA-3jr7-6hqp-x… ExploitMitigationVendor Advisory
- github.com/mesop-dev/mesop/security/advisories/GHSA-3jr7-6hqp-x… ExploitMitigationVendor Advisory
- github.com/mesop-dev/mesop/commit/760a2079b5c609038c826d24dfbcf… Patch
- github.com/mesop-dev/mesop/releases/tag/v1.2.5 ProductRelease Notes
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 55 · as of 12 November 2026
- CWE
- CWE-125CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.