flask-3.0.3-py3-none-any.whl: 1 vulnerabilities (highest severity is: 4.3)

Vulnerable Library - flask-3.0.3-py3-none-any.whl

A simple framework for building complex web applications.

Library home page: https://files.pythonhosted.org/packages/61/80/ffe1da13ad9300f87c93af113edd0638c75138c42a0994becfacac078c06/flask-3.0.3-py3-none-any.whl

Sample Path to Dependency File: /examples/trace-analytics-sample-app/sample-app/requirements.txt

Path to vulnerable library: /tmp/ws-ua_20260919124000_VHQASD/python_DOUHFS/202609191240011/env/lib/python3.10/site-packages/flask-3.0.3.dist-info

Found in HEAD commit: aff23afca7be6eb37ce42d1448e445bc8b72b853

CVE-2026-27205

Vulnerable Library - flask-3.0.3-py3-none-any.whl

A simple framework for building complex web applications.

Library home page: https://files.pythonhosted.org/packages/61/80/ffe1da13ad9300f87c93af113edd0638c75138c42a0994becfacac078c06/flask-3.0.3-py3-none-any.whl

Sample Path to Dependency File: /examples/trace-analytics-sample-app/sample-app/requirements.txt

Path to vulnerable library: /tmp/ws-ua_20260919124000_VHQASD/python_DOUHFS/202609191240011/env/lib/python3.10/site-packages/flask-3.0.3.dist-info

Dependency Hierarchy:

• ❌ flask-3.0.3-py3-none-any.whl (Vulnerable Library)

Found in HEAD commit: aff23afca7be6eb37ce42d1448e445bc8b72b853

Found in base branch: main

Vulnerability Details

Flask is a web server gateway interface (WSGI) web application framework. In versions 3.1.2 and below, when the session object is accessed, Flask should set the Vary: Cookie header., resulting in a Use of Cache Containing Sensitive Information vulnerability. The logic instructs caches not to cache the response, as it may contain information specific to a logged in user. This is handled in most cases, but some forms of access such as the Python in operator were overlooked. The severity and risk depend on the application being hosted behind a caching proxy that doesn't ignore responses with cookies, not setting a Cache-Control header to mark pages as private or non-cacheable, and accessing the session in a way that only touches keys without reading values or mutating the session. The issue has been fixed in version 3.1.3.

Publish Date: 2026-02-21

URL: CVE-2026-27205

CVSS 3 Score Details (4.3)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: Low
  • Integrity Impact: None
  • Availability Impact: None

Suggested Fix

Type: Upgrade version

Release Date: 2026-02-21

Fix Resolution: https://github.com/pallets/flask.git - 3.1.3

⛑️ Automatic Remediation will be attempted for this issue.