CVE-2026-27830 — c3p0
Fix: swaldman/c3p0@e14cbd8CVE-2026-27830 is a Code Injection vulnerability in com.mchange:c3p0. A fix is available for com.mchange:c3p0 — see the affected versions and patch details below.
c3p0 vulnerable to Remote Code Execution via unsafe deserialization of userOverridesAsString property
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-27830.
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.
Real-World Exposure
com.mchange:c3p0Real-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
c3p0 is vulnerable to attack via maliciously crafted Java-serialized objects and javax.naming.Reference instances. Several c3p0 ConnectionPoolDataSource implementations have a property called userOverridesAsString which conceptually represents a Map<String,Map<String,String>>. Prior to v0.12.0, that property was maintained as a hex-encoded serialized object. Any attacker able to reset this property, on an existing ConnectionPoolDataSource or via maliciously crafted serialized objects or javax.naming.Reference instances could be tailored execute unexpected code on the application's CLASSPATH.
The danger of this vulnerability was strongly magnified by vulnerabilities in c3p0's main dependency, mchange-commons-java. This library includes code that mirrors early implementations of JNDI functionality, including ungated support for remote factoryClassLocation values. Attackers could set c3p0's userOverridesAsString hex-encoded serialized objects that include objects "indirectly serialized" via JNDI references. Deserialization of those objects and dereferencing of the embedded javax.naming.Reference objects could provoke download and execution of malicious code from a remote factoryClassLocation.
Although hazard presented by c3p0's vulnerabilites are exarcerbated by vulnerabilities in mchange-commons-java, use of Java-serialized-object hex as the format for a writable Java-Bean property, of objects that may be exposed across JNDI interfaces, represents a serious independent fragility.
Patches
The userOverridesAsString property of c3p0 ConnectionPoolDataSource classes has been reimplemented to use a safe CSV-based format, rather than rely upon potentially dangerous Java object deserialization.
c3p0-0.12.0+ and above depend upon mchange-commons-java 0.4.0+, which gates support for remote factoryClassLocation values by configuration parameters that default to restrictive values. Those parameters are documented here.
c3p0 additionally enforces the new mchange-commons-java com.mchange.v2.naming.nameGuardClassName to prevent injection of unexpected, potentially remote JNDI names.
Workarounds
Users should upgrade to c3p0-0.12.0 or above. There is no supported workaround for earlier versions of c3p0.
References
c3p0, you little rascal — Hans-Martin Münch c3p0 documentation, security note c3p0 documentation, configuring security
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.mchange:c3p0 | all versions | 0.12.0com.mchange:c3p0:0.12.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.mchange:c3p0, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.mchange:c3p0 to 0.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27830 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-2026-27830 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-27830. 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 build of Apache Camel 4.14.4 for Spring Boot 3.5.11 | com.mchange/c3p0 | RHSA-2026:3890 |
| Red Hat JBoss Enterprise Application Platform 8.1.7.GA | org.hibernate.orm/hibernate-core:6.6.48.Final-redhat-00001 | RHSA-2026:18059 |
| Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 | eap8-hibernate-0:6.6.48-1.Final_redhat_00001.1.el8eap | RHSA-2026:18054 |
| Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 | eap8-hibernate-0:6.6.48-1.Final_redhat_00001.1.el9eap | RHSA-2026:18055 |
| Red Hat Satellite 6.18 for RHEL 9 | candlepin-0:4.6.6-1.el9sat | RHSA-2026:28385 |
Frequently Asked Questions
Is CVE-2026-27830 in your dependencies?
O3 Security finds CVE-2026-27830 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.