starcitizentools/citizen-skin allows stored XSS in user registration date message

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

EPSS

• CVE-2025-49578: 0.43% estimated exploitation activity in the next 30 days; percentile 36.90 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 1. 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.

Published by the source

13 Jun 2025, 14:09 UTC

Last modified by the source

13 Jun 2025, 14:09 UTC

Source last checked

26 Oct 2026, 14:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2v3v-3whp-953h

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# Patch Next advisory brief: CVE-2025-49578

Advisory: starcitizentools/citizen-skin allows stored XSS in user registration date message
IDs: CVE-2025-49578, GHSA-2v3v-3whp-953h
Record: https://patchnext.com/advisories/cve-2025-49578 (revision 1, source checked 26 Oct 2026, 14:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: starcitizentools/citizen-skin 3.3.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist starcitizentools/citizen-skin: affected >= 3.3.0, < 3.3.1; fixed in 3.3.1

## Suggested inspection (read-only)
- Packagist starcitizentools/citizen-skin: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on starcitizentools/citizen-skin.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2v3v-3whp-953h (GitHub-reviewed advisory GHSA-2v3v-3whp-953h lists affected ranges: Packagist starcitizentools/citizen-skin >=3.3.0 <3.3.1)

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