GHSA-529p-jj47-w3m3
MEDIUMDecidim cross-site scripting (XSS) in the admin panel
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
decidim-admin💎decidim-adminReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The admin panel is subject to potential XSS attach in case the attacker manages to modify some records being uploaded to the server.
The attacker is able to change e.g. to <svg onload=alert('XSS')> if they know how to craft these requests themselves. And then enter the returned blob ID to the form inputs manually by modifying the edit page source.
Patches
Available in versions 0.27.6 and 0.28.1.
Workarounds
Review the user accounts that have access to the admin panel (i.e. general Administrators, and participatory space's Administrators) and remove access to them if they don't need it.
References
OWASP ASVS v4.0.3-5.1.3
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | decidim-admin | all versions | 0.27.6 |
| 💎RubyGems | decidim-admin | ≥ 0.28.0.rc1&&< 0.28.1 | 0.28.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for decidim-admin. 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 decidim-admin to 0.27.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-529p-jj47-w3m3 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-529p-jj47-w3m3 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-529p-jj47-w3m3. 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-529p-jj47-w3m3 in your dependencies?
O3 detects GHSA-529p-jj47-w3m3 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.