CVE-2023-6379 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in org.opencms:opencms-core. A fix is available for org.opencms:opencms-core — see the affected versions and patch details below.
Cross-site Scripting in Alkacon Software OpenCms
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-6379.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.opencms:opencms-coreReal-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
Cross-site scripting (XSS) vulnerability in Alkacon Software Open CMS, affecting versions 14 and 15 of the 'Mercury' template. This vulnerability could allow a remote attacker to send a specially crafted JavaScript payload to a victim and partially take control of their browsing session.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.opencms:opencms-core | ≥ 14.0.0&&< 16.0.0 | 16.0.0org.opencms:opencms-core:16.0.0 |
Affected Products
opencmsalkaconDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.opencms:opencms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.opencms:opencms-core to 16.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6379 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
How to detect CVE-2023-6379
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2023-6379 -u https://target- Template
- OpenCMS 14 & 15 - Cross Site Scripting
- Severity
- medium
- Impact
- Unauthenticated attackers can inject malicious JavaScript through multiple parameters in OpenCMS Mercury template pages to steal user session cookies and execute attacks against OpenCMS users.
- Remediation
- Update to version OpenCMS 16
Template by ProjectDiscovery nuclei-templates (msegoviag), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2023-6379 in your dependencies?
Find it across Maven, including transitive dependencies.