CVE-2026-15034: Flask-MonitoringDashboard CSRF Vulnerability

CVE-2026-15034 Overview

CVE-2026-15034 is a Cross-Site Request Forgery (CSRF) vulnerability affecting flask-dashboard/Flask-MonitoringDashboard versions up to and including 5.0.2. The flaw resides in unspecified functionality of the dashboard and allows a remote attacker to trick an authenticated user into submitting unintended state-changing requests. The exploit has been publicly disclosed, and the maintainers were notified through a GitHub issue report but have not yet responded. The weakness is classified under CWE-352: Cross-Site Request Forgery.

Critical Impact
Remote attackers can perform unauthorized state-changing actions in Flask-MonitoringDashboard by leveraging an authenticated victim's browser session, requiring only user interaction such as visiting a malicious page.

Affected Products

flask-dashboard Flask-MonitoringDashboard versions up to 5.0.2
Web applications embedding Flask-MonitoringDashboard as a monitoring blueprint
Deployments exposing the dashboard endpoints to authenticated users over the network

Discovery Timeline

2026-07-08 - CVE-2026-15034 published to NVD
2026-07-08 - Last updated in NVD database

Technical Details for CVE-2026-15034

Vulnerability Analysis

Flask-MonitoringDashboard is a Flask extension that provides runtime performance monitoring and administrative controls for Flask applications. The vulnerability allows an attacker to craft a malicious HTML page or link that, when visited by an authenticated dashboard user, forces the victim's browser to issue authenticated requests to dashboard endpoints. Because the affected endpoints do not adequately validate the origin of the request or require an unpredictable anti-CSRF token, the server processes the forged request as legitimate. The result is limited integrity impact on dashboard configuration or monitored data, with no direct confidentiality or availability consequence.

Root Cause

The root cause is missing CSRF protection on state-changing HTTP endpoints in Flask-MonitoringDashboard through version 5.0.2. The application relies on session cookies for authentication without enforcing a synchronizer token, double-submit cookie, or SameSite request validation. Browsers automatically attach the session cookie to cross-origin requests, allowing forged requests to be authenticated on behalf of the victim.

Attack Vector

Exploitation requires an authenticated dashboard user to interact with attacker-controlled content, such as clicking a link or loading an image tag pointing at a crafted URL. The attacker hosts a page that triggers GET or POST requests against Flask-MonitoringDashboard endpoints. When the victim's browser sends the request, the session cookie is included, and the server executes the requested action under the victim's privileges. No credentials are transmitted to the attacker; the attack abuses ambient authority in the browser. See the GitHub issue #557 and VulDB entry for CVE-2026-15034 for additional technical context.

Detection Methods for CVE-2026-15034

Indicators of Compromise

HTTP requests to Flask-MonitoringDashboard endpoints containing a Referer or Origin header pointing at unexpected external domains.
State-changing requests to dashboard routes lacking any anti-CSRF token parameter or header.
Unexpected configuration changes or administrative actions in dashboard audit logs correlated with a user's normal browsing session.

Detection Strategies

Inspect web server and application access logs for cross-origin POST, PUT, or DELETE requests targeting Flask-MonitoringDashboard routes.
Deploy a Web Application Firewall (WAF) rule that flags authenticated requests to dashboard endpoints when Origin or Referer does not match the application's own domain.
Correlate authentication session identifiers with request origins to identify sessions issuing requests from unrelated referrers.

Monitoring Recommendations

Enable verbose request logging for all Flask-MonitoringDashboard blueprint routes, including headers relevant to CSRF assessment.
Alert on administrative actions such as endpoint enable/disable or configuration updates that occur without a preceding dashboard navigation event.
Forward web application logs to a centralized analytics or SIEM platform to enable long-term correlation and anomaly detection.

How to Mitigate CVE-2026-15034

Immediate Actions Required

Restrict access to Flask-MonitoringDashboard so that only authenticated administrators on trusted networks can reach dashboard routes.
Configure the application session cookie with SameSite=Strict or SameSite=Lax and the Secure attribute to reduce cross-site request exposure.
Require reauthentication or step-up authentication before performing sensitive dashboard operations.

Patch Information

At the time of publication, the Flask-MonitoringDashboard maintainers have not released a fix for CVE-2026-15034. Monitor the Flask-MonitoringDashboard GitHub repository and GitHub issue #557 for updates. Once a patched release is available, upgrade beyond version 5.0.2.

Workarounds

Place the dashboard behind a reverse proxy that enforces Origin and Referer header validation for state-changing requests.
Integrate Flask-WTF CSRF protection at the application level and apply it to the Flask-MonitoringDashboard blueprint routes.
Bind the dashboard to an internal-only network interface or protect it with a VPN or mutual TLS to prevent exposure to attacker-influenced browsers.

bash

# Configuration example: enforce SameSite cookies and CSRF protection in a Flask app
# app.py
from flask import Flask
from flask_wtf.csrf import CSRFProtect
import flask_monitoringdashboard as dashboard

app = Flask(__name__)
app.config.update(
    SESSION_COOKIE_SAMESITE="Strict",
    SESSION_COOKIE_SECURE=True,
    WTF_CSRF_ENABLED=True,
)

csrf = CSRFProtect(app)
dashboard.bind(app)
csrf.exempt(dashboard.blueprint)  # then wrap sensitive routes with a reverse-proxy CSRF check