CVE-2026-46556

Received Received - Intake

SSRF in FlaskBB Forum Software

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: GitHub, Inc.

Description

FlaskBB is a Forum Software written in Python using the micro framework Flask. Prior to version 2.2.1, a Server-Side Request Forgery (SSRF) vulnerability in get_image_info() allows any authenticated user to force the server to send HTTP requests to arbitrary internal endpoints, including cloud metadata services. This is a blind SSRF with confirmed internal port scanning and internal API triggering capabilities. Version 2.2.1 patches the issue.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-21

Last Modified

2026-07-21

Generated

2026-07-22

AI Q&A

2026-07-22

EPSS Evaluated

N/A

NVD

CVE-2026-46556

Affected Vendors & Products

Vendor	Product	Version / Range
flaskbb	flaskbb	to 2.2.1 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

Executive Summary

FlaskBB before version 2.2.1 has a Server-Side Request Forgery (SSRF) vulnerability in the get_image_info() function. This allows authenticated users to make the server send HTTP requests to internal endpoints, including cloud metadata services. It is a blind SSRF that can perform internal port scanning and trigger internal APIs.

Detection Guidance

Detecting this SSRF vulnerability requires checking FlaskBB versions and monitoring network traffic. First, verify if your FlaskBB instance is running version 2.2.1 or later. If not, the vulnerability likely exists. Use commands like 'pip show flaskbb' to check the installed version. Monitor server logs for unusual HTTP requests to internal endpoints or cloud metadata services.

Impact Analysis

An attacker with access could exploit this to scan internal networks, access sensitive internal APIs, or interact with cloud metadata services. This may lead to unauthorized data exposure or further network compromise depending on the internal setup.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection principles or HIPAA's security requirements for protected health information. Organizations may face compliance violations if exploited.

Mitigation Strategies

Immediately upgrade FlaskBB to version 2.2.1 or later to patch the SSRF vulnerability. If upgrading is not possible, restrict network access to internal endpoints and cloud metadata services. Review and filter user-uploaded content to prevent SSRF payloads. Monitor network traffic for suspicious requests.

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