CVE-2026-77143
Received Received - Intake

Frontend Topic Editing Allows Unauthorized Content Overwrite

Publication date: 2026-08-25

Last updated on: 2026-08-25

Assigner: TYPO3

Description
The frontend topic editing flow does not verify on the server side that the requesting visitor owns the topic being modified. As a result, a visitor who knows the identifier of a topic from the public forum can submit a modified update request for that topic directly and overwrite its content, without the application confirming ownership. Topic identifiers are visible in the public forum listing, and exploitation requires no privileged access or non-default configuration.

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Meta Information

Published
2026-08-25
Last Modified
2026-08-25
Generated
2026-08-25
AI Q&A
2026-08-25
EPSS Evaluated
N/A
NVD
CVE-2026-77143
EUVD
EUVD-2026-65333

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
typo3 forum to 6.2.4 (exc)
typo3 forum to 6.2.3 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-639 The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

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Executive Summary

This vulnerability is a Broken Access Control issue in the TYPO3 extension 'Forum' (pforum). It allows attackers to modify forum topics without proper authorization because the server does not verify if the requesting visitor owns the topic being edited. Attackers only need to know the topic's identifier, which is publicly visible, to submit unauthorized updates.

Detection Guidance

Check if the TYPO3 extension 'Forum' (pforum) version 6.2.3 or below is installed. Review server logs for unauthorized topic update requests or unexpected modifications to forum topics.

Impact Analysis

Attackers could overwrite the content of forum topics, leading to misinformation, defacement, or unauthorized changes. Since topic identifiers are public, any visitor can exploit this without needing special access or configuration changes.

Compliance Impact

This vulnerability could lead to unauthorized modification of forum content, potentially violating data integrity principles in GDPR and HIPAA. If sensitive data is altered without authorization, it may result in non-compliance with these regulations due to improper access controls.

Mitigation Strategies

Update the TYPO3 extension 'Forum' (pforum) to version 6.2.4 or later immediately. Remove or restrict access to the frontend topic editing feature if not required.

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