CVE-2026-52771
Received Received - Intake

SQL Injection in YesWiki via Page Tag Deletion

Publication date: 2026-09-05

Last updated on: 2026-09-05

Assigner: GitHub, Inc.

Description
YesWiki is a wiki system written in PHP. From version 4.2.0 to before version 4.6.6, ApiController::deletePage() interpolates a page tag retrieved from the database into a DELETE FROM …_links WHERE to_tag = '$tag' query without escaping. The page tag is attacker-controlled — the POST /api/pages/{tag} API accepts arbitrary URL-encoded values, including single quotes, and stores them. A low-privilege authenticated user can therefore create a page whose tag is a SQL fragment, make the page non-orphaned via the standard {{include page="…"}} link mechanism, and then invoke the delete endpoint to execute arbitrary SQL inside the wiki database - including time-based blind data exfiltration from any table. This issue has been patched in version 4.6.6.

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Meta Information

Published
2026-09-05
Last Modified
2026-09-05
Generated
2026-09-05
AI Q&A
2026-09-05
EPSS Evaluated
N/A
NVD
CVE-2026-52771

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
yeswiki yeswiki to 4.6.6 (exc)
yeswiki yeswiki 4.6.6

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-89 The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.

Attack-Flow Graph

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Executive Summary

YesWiki versions 4.2.0 to 4.6.5 have a SQL injection flaw in ApiController::deletePage(). The function uses a page tag from the database in a DELETE query without proper escaping. Attackers can exploit this by creating a page with a malicious tag containing SQL code, then triggering the delete endpoint to execute arbitrary SQL commands in the database.

Detection Guidance

This vulnerability can be detected by checking the YesWiki version installed on your system. If the version is between 4.2.0 and 4.6.5, it is vulnerable. Run the command: grep -r 'YesWiki' /path/to/yeswiki/installation to locate the version. Additionally, monitor database queries for unusual patterns or time delays that may indicate SQL injection attempts.

Impact Analysis

A low-privilege authenticated user could exploit this to read, modify, or delete sensitive data in the wiki database. This includes extracting information through time-based blind SQL injection, even from unrelated tables. The attacker could gain unauthorized access to confidential information stored in the database.

Compliance Impact

This vulnerability could lead to unauthorized data access or exfiltration, violating GDPR's data protection principles and HIPAA's security requirements for protected health information. Organizations using affected YesWiki versions may face compliance violations, legal penalties, and reputational damage due to potential data breaches.

Mitigation Strategies

Immediately upgrade YesWiki to version 4.6.6 or later to patch the vulnerability. If upgrading is not possible, restrict access to the POST /api/pages/{tag} endpoint and sanitize user inputs to prevent SQL injection. Review database user permissions to limit potential damage from unauthorized queries.

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