CVE-2018-11326 — joomla/joomla-cms
MEDIUMCVE-2018-11326 is a medium-severity (CVSS 4.8) Cross-site Scripting (XSS) vulnerability in joomla/joomla-cms. A fix is available for joomla/joomla-cms — see the affected versions and patch details below.
Joomla! XSS Vulnerability
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.
How urgent is this, really
CVE-2018-11326 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
joomla/joomla-cmsReal-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
An issue was discovered in Joomla! Core starting in 3.0.0 and prior to 3.8.8. Inadequate input filtering leads to a multiple XSS vulnerabilities. Additionally, the default filtering settings could potentially allow users of the default Administrator user group to perform a XSS attack.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | joomla/joomla-cms | ≥ 3.0.0&&< 3.8.8 | 3.8.8composer require joomla/joomla-cms:^3.8.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for joomla/joomla-cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update joomla/joomla-cms to 3.8.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-11326 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-11326 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2018-11326. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-11326 in your dependencies?
O3 Security finds CVE-2018-11326 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.