Skip to main content

Mesop CVE-2026-77357

| EUVDEUVD-2026-66114 HIGH
Uncontrolled Resource Consumption (CWE-400)
2026-08-25 GitHub_M
Python Denial Of Service Mesop
8.7
CVSS 4.0 · Vendor: GitHub_M
Share

Severity by source

Vendor (GitHub_M) PRIMARY
8.7 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vuln.today AI
7.5 HIGH

Network-reachable unauthenticated GET endpoint; no scope change as only the Mesop process is affected; pure availability impact from thread exhaustion with no data exposure.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

4
Patch available
Aug 25, 2026 - 22:04 EUVD
Source Code Evidence Fetched
Aug 25, 2026 - 21:21 vuln.today
Analysis Generated
Aug 25, 2026 - 21:21 vuln.today
CVE Published
Aug 25, 2026 - 20:40 cve.org
HIGH 8.7

DescriptionCVE.org

Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.3, applications running in debug mode expose a GET /hot-reload endpoint whose unbounded loop depends on the user-supplied counter parameter, allowing an unauthenticated attacker to hold worker threads with high counter values until the worker pool is exhausted and the server becomes unavailable. A single unauthenticated attacker can crash the Mesop server with minimal effort. Because the attack leverages worker exhaustion, the server remains unresponsive until it is manually restarted. This issue is fixed in version 1.3.3.

AnalysisAI

Worker-thread exhaustion in Mesop's debug-mode hot-reload endpoint (prior to version 1.3.3) allows an unauthenticated remote attacker to render the server completely unavailable with minimal effort. The GET /hot-reload endpoint in debug mode enters an unbounded loop controlled by the attacker-supplied counter parameter, holding worker threads indefinitely until the thread pool is exhausted and the server stops responding to all requests. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts
Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Identify Mesop server running in debug mode
Delivery
Send concurrent GET /hot-reload?counter=<large_integer> requests
Exploit
Each request blocks a worker thread in unbounded loop
Execution
Exhaust server worker pool
Persist
Server unresponsive to all traffic
Impact
Manual restart required to recover
Sign in to reveal

Vulnerability AssessmentAI

Exploitation Exploitation strictly requires that the Mesop application is running with debug mode enabled - this is the sole non-default configuration that exposes the /hot-reload endpoint. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 vector AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N scoring 8.7 accurately reflects the attack characteristics: network-reachable, no complexity or privileges, fully automatable, with high availability impact and no confidentiality or integrity loss. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker discovers a Mesop application running in debug mode on a reachable HTTP port and sends repeated concurrent GET requests to /hot-reload?counter=999999999. Each request ties up a server worker thread in an infinite loop awaiting a counter increment that never arrives; after sending enough concurrent requests to fill the worker pool, the server becomes unresponsive to all legitimate traffic. …
Remediation Upgrade to Mesop version 1.3.3, which is the vendor-confirmed fixed release available at https://github.com/mesop-dev/mesop/releases/tag/v1.3.3. … Detailed patch versions, workarounds, and compensating controls in full report.
Sign in to read full assessment

Recommended ActionAI

Within 24 hours, immediately disable debug mode on all production Mesop instances and verify configuration change across all deployments. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

More in Python

View all
CVE-2025-24016 CRITICAL POC
9.9 Feb 10

Wazuh SIEM platform versions 4.4.0 through 4.9.0 contain an unsafe deserialization vulnerability in the DistributedAPI t
CVE-2025-27520 CRITICAL POC
9.8 Apr 04

BentoML version 1.4.2 and earlier contains an unauthenticated remote code execution vulnerability through insecure deser
CVE-2025-2945 CRITICAL POC
9.9 Apr 03

pgAdmin 4 contains critical remote code execution vulnerabilities in the Query Tool download and Cloud Deployment endpoi
CVE-2013-5093 MEDIUM POC
6.8 Sep 27

The renderLocalView function in render/views.py in graphite-web in Graphite 0.9.5 through 0.9.10 uses the pickle Python

CVE-2025-32375 CRITICAL POC
9.8 Apr 09

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Rated critica
CVE-2014-0224 HIGH POC
7.4 Jun 05

OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h does not properly restrict processing of ChangeCiph
CVE-2024-21644 HIGH POC
7.5 Jan 08

pyLoad download manager version prior to 0.5.0b3.dev77 exposes the Flask SECRET_KEY through an unauthenticated endpoint.
CVE-2026-33017 CRITICAL POC
9.3 Mar 17

Langflow (a visual LLM pipeline builder) contains a critical unauthenticated code execution vulnerability (CVE-2026-3301
CVE-2017-9462 HIGH POC
8.8 Jun 06

In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and conse
CVE-2026-39987 CRITICAL POC
9.3 Apr 08

Unauthenticated remote code execution in Marimo ≤0.20.4 allows attackers to execute arbitrary system commands via the `/
CVE-2024-21645 MEDIUM POC
5.3 Jan 08

pyLoad is the free and open-source Download Manager written in pure Python. Rated medium severity (CVSS 5.3), this vulne
CVE-2026-55255 HIGH POC
8.4 Jun 19

Cross-user flow execution in Langflow (< 1.9.1) lets any authenticated API-key holder run another user's flow by passing

Same weakness CWE-400 – Uncontrolled Resource Consumption

View all
CVE-2023-44487 HIGH POC
7.5
CVE-2026-45498 HIGH POC
7.5
CVE-2016-8610 HIGH
7.5
CVE-2026-28318 HIGH POC
7.5
CVE-2023-38180 HIGH
7.5
CVE-2025-26673 HIGH
7.5
CVE-2015-7978 HIGH
7.5
CVE-2025-27473 HIGH
7.5

Same technique Denial Of Service

View all
CVE-2015-5119 CRITICAL POC
9.8
CVE-2011-2462 CRITICAL POC
9.8
CVE-2011-0611 HIGH POC
8.8
CVE-2012-1889 HIGH POC
8.8
CVE-2012-0507 CRITICAL POC
9.8
CVE-2014-1761 HIGH POC
7.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2011-0609 HIGH POC
7.8

Share

CVE-2026-77357 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy