CVE-2025-49578 is a medium-severity (CVSS 6.5) Cross-site Scripting (XSS) vulnerability in starcitizentools/citizen-skin. A fix is available for starcitizentools/citizen-skin — see the affected versions and patch details below.
Citizen allows stored XSS in user registration date message
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-49578.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
starcitizentools/citizen-skinReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Various date messages returned by Language::userDate are inserted into raw HTML, allowing anybody who can edit those messages to insert arbitrary HTML into the DOM.
Details
The result of $this->lang->userDate( $timestamp, $this->user ) returns unescaped values, but is inserted as raw HTML by Citizen:
https://github.com/StarCitizenTools/mediawiki-skins-Citizen/blob/072e4365e9084e4b153eac62d3666566c06f5a49/includes/Components/CitizenComponentUserInfo.php#L55-L60
PoC
- Go to any page using citizen with the uselang parameter set to x-xss and while being logged in
Depending on the registration date of the account you're logged in with, various messages can be shown. In my case, it's
november:
Impact
This impacts wikis where a group has the editinterface but not the editsitejs user right.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | starcitizentools/citizen-skin | ≥ 3.3.0&&< 3.3.1 | 3.3.1composer require starcitizentools/citizen-skin:^3.3.1 |
Affected Products
citizenstarcitizen.toolsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starcitizentools/citizen-skin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update starcitizentools/citizen-skin to 3.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49578 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2025-49578 in your dependencies?
Find it across Packagist, including transitive dependencies.