CVE-2020-15179: Scratch-Wiki Scratchsig

Critical severity, CVSS 9.0. EPSS: 1.2% chance of exploitation in the next 30 days.

The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using <script> tag inside <scratchsig> tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript API, this can potentially lead to privilege escalation and/or account takeover. This has been patched in release 1.0.1. This has already been deployed to all Scratch Wikis. No workarounds exist other than disabling the extension completely.

Affected products

Published 2020-09-15. Last modified 2026-06-17.