Flask-2.2.5-py3-none-any.whl: 1 vulnerabilities (highest severity is: 4.3)

[mend-bolt-for-github]

Vulnerable Library - Flask-2.2.5-py3-none-any.whl

A simple framework for building complex web applications.

Library home page: https://files.pythonhosted.org/packages/9f/1a/8b6d48162861009d1e017a9740431c78d860809773b66cac220a11aa3310/Flask-2.2.5-py3-none-any.whl

Path to dependency file: /requirements.txt

Path to vulnerable library: /requirements.txt

Found in HEAD commit: 46b2b180777accd8b00c59f7f7b3dae4eeecfed2

Vulnerabilities

Vulnerability	Severity	CVSS	Dependency	Type	Fixed in (Flask version)	Remediation Possible**
CVE-2026-27205	Medium	4.3	Flask-2.2.5-py3-none-any.whl	Direct	https://github.com/pallets/flask.git - 3.1.3	❌

**In some cases, Remediation PR cannot be created automatically for a vulnerability despite the availability of remediation

Details

CVE-2026-27205

Vulnerable Library - Flask-2.2.5-py3-none-any.whl

A simple framework for building complex web applications.

Library home page: https://files.pythonhosted.org/packages/9f/1a/8b6d48162861009d1e017a9740431c78d860809773b66cac220a11aa3310/Flask-2.2.5-py3-none-any.whl

Path to dependency file: /requirements.txt

Path to vulnerable library: /requirements.txt

Dependency Hierarchy:

• ❌ Flask-2.2.5-py3-none-any.whl (Vulnerable Library)

Found in HEAD commit: 46b2b180777accd8b00c59f7f7b3dae4eeecfed2

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

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-02-21

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

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