CVE-2025-62508: Citizen vulnerable to stored XSS in sticky header button messages

Vulnerability summary

CVE-2025-62508 is a medium (CVSS 6.5) Cross-site Scripting vulnerability in starcitizentools mediawiki-skins-citizen. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.9% of scored vulnerabilities.

Timeline

1. 17-10-2025
   PublishedVulnerability first disclosed.
2. 17-10-2025
   Last modifiedVulnerability information updated.

Description

Citizen is a MediaWiki skin that makes extensions part of the cohesive experience. Citizen from 3.3.0 to 3.9.0 are vulnerable to stored cross-site scripting in the sticky header button message handling. In stickyHeader.js the copyButtonAttributes function assigns innerHTML from a source element’s textContent when copying button labels. This causes escaped HTML in system message content (such as citizen-share, citizen-view-history, citizen-view-edit, and nstab-talk) to be interpreted as HTML in the sticky header, allowing injection of arbitrary script by a user with the ability to edit interface messages. The vulnerability allows a user with the editinterface right but without the editsitejs right (by default the sysop group has editinterface but may not have editsitejs) to execute arbitrary JavaScript in other users’ sessions, enabling unauthorized access to sensitive data or actions. The issue is fixed in 3.9.0.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')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.