CVE-2016-6796 is a high-severity (CVSS 7.5) vulnerability in org.apache.tomcat:tomcat. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.
Apache Tomcat vulnerable to SecurityManager bypass
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-2016-6796 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
org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcatReal-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
A malicious web application running on Apache Tomcat 9.0.0.M1 to 9.0.0.M9, 8.5.0 to 8.5.4, 8.0.0.RC1 to 8.0.36, 7.0.0 to 7.0.70 and 6.0.0 to 6.0.45 was able to bypass a configured SecurityManager via manipulation of the configuration parameters for the JSP Servlet.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | ≥ 9.0.0.M1&&< 9.0.0.M10 | 9.0.0.M10org.apache.tomcat:tomcat:9.0.0.M10 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 8.5.0&&< 8.5.5 | 8.5.5org.apache.tomcat:tomcat:8.5.5 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 8.0.0.RC1&&< 8.0.37 | 8.0.37org.apache.tomcat:tomcat:8.0.37 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 7.0.0&&< 7.0.71 | 7.0.71org.apache.tomcat:tomcat:7.0.71 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 6.0.0&&< 6.0.46 | 6.0.46org.apache.tomcat:tomcat:6.0.46 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 9.0.0.M10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-6796 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-2016-6796 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2016-6796. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 7 | tomcat-0:7.0.76-2.el7 | RHSA-2017:2247 |
| Red Hat JBoss Enterprise Application Platform 6.4 | see advisory | RHSA-2017:1551 |
| Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 5 | hornetq-0:2.3.25-21.SP19_redhat_1.1.ep6.el5 | RHSA-2017:1550 |
| Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 6 | hornetq-0:2.3.25-21.SP19_redhat_1.1.ep6.el6 | RHSA-2017:1549 |
| Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 6 | jboss-ec2-eap-0:7.5.16-1.Final_redhat_1.ep6.el6 | RHSA-2017:1552 |
| Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 7 | hornetq-0:2.3.25-21.SP19_redhat_1.1.ep6.el7 | RHSA-2017:1548 |
| Red Hat JBoss Web Server 3.1 | see advisory | RHSA-2017:0457 |
| Red Hat JBoss Web Server 3 for RHEL 6 | hibernate4-eap6-0:4.2.23-1.Final_redhat_1.1.ep6.el6 | RHSA-2017:0455 |
Frequently Asked Questions
Is CVE-2016-6796 in your dependencies?
O3 Security finds CVE-2016-6796 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.