GHSA-5c66-v29h-xjh8
CRITICALGHSA-5c66-v29h-xjh8 is a critical-severity (CVSS 9.6) Cross-site Scripting (XSS) vulnerability in org.xwiki.platform:xwiki-platform-oldcore. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-5c66-v29h-xjh8 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XSS Cross Site Scripting
Real-World Exposure
org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-web☕org.xwiki.platform:xwiki-platform-webReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
It is possible to persistently inject scripts in XWiki.
For unregistred users:
- By filling simple text fields
For registered users:
- By filling their personal information
- (if they have edit rights) By filling the values of static lists using App Within Minutes
That can lead to user's session hijacking, and if used in conjunction with a social engineering attack it can also lead to disclosure of sensitive data, CSRF attacks and other security vulnerabilities. That can also lead to the attacker taking over an account. If the victim has administrative rights it might even lead to code execution on the server, depending on the application and the privileges of the account.
Patches
It has been patched on XWiki 12.8 and 12.6.3.
Workarounds
There is no easy workaround except upgrading XWiki.
References
https://jira.xwiki.org/browse/XWIKI-17374
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira XWiki
- Email us at our security mailing list
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xwiki.platform:xwiki-platform-oldcore | all versions | 12.6.3 |
| ☕Maven | org.xwiki.platform:xwiki-platform-oldcore | ≥ 12.6.4&&< 12.8 | 12.8 |
| ☕Maven | org.xwiki.platform:xwiki-platform-web | all versions | 12.6.3 |
| ☕Maven | org.xwiki.platform:xwiki-platform-web | ≥ 12.6.4&&< 12.8 | 12.8 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore. 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 org.xwiki.platform:xwiki-platform-oldcore to 12.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5c66-v29h-xjh8 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-5c66-v29h-xjh8 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-5c66-v29h-xjh8. 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-5c66-v29h-xjh8 in your dependencies?
O3 detects GHSA-5c66-v29h-xjh8 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.