CVE-2026-27830 swaldman CVE debrief

Who should care

Defenders and developers using the c3p0 library should assess their exposure and verify if they are using a vulnerable version. This vulnerability may impact applications that use c3p0 for JDBC Connection pooling.

Why it matters

The c3p0 library vulnerability allows attackers to execute unexpected code on the application's CLASSPATH via maliciously crafted Java-serialized objects and JNDI references. Defenders and developers should assess their exposure, verify vulnerable versions, and upgrade to c3p0 version 0.12.0 or later to mitigate the vulnerability.

• Verify and restrict use of `userOverridesAsString` property to prevent code execution
• Assess exposure and upgrade to c3p0 version 0.12.0 or later to mitigate vulnerability
• Monitor for suspicious activity related to Java-serialized objects and JNDI references
• Review and restrict JNDI references to prevent remote code execution

Technical summary

The c3p0 library, a JDBC Connection pooling library, is vulnerable to attack via maliciously crafted Java-serialized objects and `javax.naming.Reference` instances. This vulnerability allows attackers to execute unexpected code on the application's CLASSPATH. The `userOverridesAsString` property of c3p0 `ConnectionPoolDataSource` classes was previously maintained as a hex-encoded serialized object, which posed a risk. The vulnerability was mitigated in c3p0 version 0.12.0, which changed the `userOverridesAsString` property to use a safe CSV-based format.

Defensive priority

High

Recommended defensive actions

• Assess exposure by verifying if using c3p0 versions prior to 0.12.0
• Upgrade to c3p0 version 0.12.0 or later
• Review and restrict use of `userOverridesAsString` property
• Monitor for suspicious activity related to Java-serialized objects and JNDI references
• Perform vulnerability scanning to identify potentially affected systems
• Implement additional logging and monitoring to detect potential exploitation attempts
• Review and update incident response plans to address potential exploitation of this vulnerability

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. The vendor, swaldman, has provided information on the mitigation of the vulnerability in c3p0 version 0.12.0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.