GHSA-prmv-7r8c-794g
HIGHCitizen vulnerable to Stored XSS through short descriptions
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
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
Short descriptions set via the ShortDescription extension are inserted as raw HTML by the Citizen skin, allowing any user to insert arbitrary HTML into the DOM by editing a page.
Details
The shortdesc property, which contains unsanitized user input, is retrieved from the OutputPage and returned as the tagline:
https://github.com/StarCitizenTools/mediawiki-skins-Citizen/blob/0d8a44011e02a081618359a1e90f462478e807aa/includes/Components/CitizenComponentPageHeading.php#L249-L251
The tagline is then provided to the template data:
https://github.com/StarCitizenTools/mediawiki-skins-Citizen/blob/0d8a44011e02a081618359a1e90f462478e807aa/includes/Components/CitizenComponentPageHeading.php#L270-L275
The template then inserts the tagline into raw HTML without doing any escaping:
https://github.com/StarCitizenTools/mediawiki-skins-Citizen/blob/0d8a44011e02a081618359a1e90f462478e807aa/templates/PageHeading.mustache#L12
PoC
- Enable Citizen and ShortDescription
- Add
{{SHORTDESC:<img src="" onerror="alert('citizen shortdescription xss')">}}to a page - Visit the page
Impact
Arbitrary HTML can be inserted into the DOM by any user, allowing for JavaScript to be executed.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | starcitizentools/citizen-skin | ≥ 1.9.4&&< 3.4.0 | 3.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starcitizentools/citizen-skin. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update starcitizentools/citizen-skin to 3.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-prmv-7r8c-794g is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-prmv-7r8c-794g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-prmv-7r8c-794g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-prmv-7r8c-794g in your dependencies?
O3 detects GHSA-prmv-7r8c-794g across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.