CVE-2026-34824Public exploitNetwork attack vector

Application crash via unbounded WebSocket thread creation

Published Apr 3, 2026 · Updated Apr 3, 2026

Uncontrolled resource consumption in Mesop 1.2.3 through versions before 1.2.5 allows remote attackers to crash applications via WebSocket floods. The handle_websocket function in mesop/server/server.py starts a new threading.Thread for every parsed ui_request without a pool, queue, backpressure, or per-connection limit. A single unauthenticated connection can exhaust operating-system threads and memory, making the entire Mesop application unavailable.

CVSS severity7.5
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Uncontrolled resource consumption in Mesop 1.2.3 through versions before 1.2.5 allows remote attackers to crash applications via WebSocket floods. The handle_websocket function in mesop/server/server.py starts a new threading.Thread for every parsed ui_request without a pool, queue, backpressure, or per-connection limit. A single unauthenticated connection can exhaust operating-system threads and memory, making the entire Mesop application unavailable.

The record

CVE
CVE-2026-34824
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
mesop-dev
Product
Mesop
Classifications
CWE-770, CWE-400, CWE-125, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.2.3, < 1.2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

mesop-dev · Mesopversion=>= 1.2.3, < 1.2.5

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CWE-400Uncontrolled Resource Consumption
CWE-125Out-of-bounds Read
T1499.003Application Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo