CVE-2026-100521
Deferred Deferred - Pending Action

Reflected XSS in Cotonti Search Plugin

Publication date: 2026-09-26

Last updated on: 2026-09-26

Assigner: VulnCheck

Description
Cotonti through 1.0.0 contains a reflected cross-site scripting vulnerability in the search plugin highlight parameter that performs no HTML or JavaScript escaping. Attackers can craft malicious links with injected JavaScript in the highlight parameter that executes in the browser of any visitor who opens the link, including administrators.

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Meta Information

Published
2026-09-26
Last Modified
2026-09-26
Generated
2026-09-26
AI Q&A
2026-09-26
EPSS Evaluated
N/A
NVD
CVE-2026-100521
EUVD
EUVD-2026-87376

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
cotonti cotonti to 1.0.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

CVE-2026-100521 is a reflected cross-site scripting (XSS) vulnerability in Cotonti through version 1.0.0. It occurs in the search plugin's highlight parameter, which does not properly escape user input. Attackers can craft malicious links with JavaScript code in the highlight parameter. When a user clicks the link, the injected script executes in their browser, potentially affecting administrators or other users.

Detection Guidance

To detect this vulnerability, inspect web server logs for requests containing the 'highlight' parameter with suspicious JavaScript payloads. Check Cotonti CMS installations for versions up to 1.0.0. Use tools like grep to search logs: grep -i 'highlight=' /var/log/apache2/access.log or similar paths. Also review the search.plugin files for unsanitized input handling.

Impact Analysis

This vulnerability allows attackers to inject malicious JavaScript into web pages viewed by users. If you click a crafted link, the script could steal cookies, session tokens, or sensitive data. It may also enable unauthorized actions on your behalf, such as changing settings or accessing restricted information. Administrators are particularly at risk as the attack could compromise the entire system.

Compliance Impact

This vulnerability could lead to data breaches, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Organizations may face fines, legal liabilities, and reputational damage if exploited. Compliance with these regulations requires proper security measures, including input validation and output escaping.

Mitigation Strategies

Immediately update Cotonti to a patched version beyond 1.0.0, specifically applying pull request #1908. If updating is not possible, disable the search plugin or sanitize the 'highlight' parameter input by escaping HTML/JavaScript. Implement a web application firewall to block XSS payloads in the 'highlight' parameter.

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