CVE-2026-27830: CWE-502: Deserialization of Untrusted Data in swaldman c3p0
c3p0, a JDBC Connection pooling library, 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. 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. c3p0 additionally enforces the new mchange-commons-java `com.mchange.v2.naming.nameGuardClassName` to prevent injection of unexpected, potentially remote JNDI names. There is no supported workaround for versions of c3p0 prior to 0.12.0.
AI Analysis
Technical Summary
The c3p0 library versions before 0.12.0 maintain the userOverridesAsString property as a hex-encoded serialized object representing a Map structure. An attacker able to manipulate this property, either on an existing ConnectionPoolDataSource or through crafted serialized objects or javax.naming.Reference instances, can cause the application to deserialize malicious data. This leads to arbitrary code execution on the application's CLASSPATH. The vulnerability is exacerbated by mchange-commons-java's early JNDI implementation that allows remote factoryClassLocation values, enabling attackers to cause the application to download and execute malicious code remotely. The vulnerability is tracked as CWE-502 (Deserialization of Untrusted Data) and CWE-94 (Code Injection).
Potential Impact
Successful exploitation allows an attacker with low privileges and adjacent network access to execute arbitrary code within the context of the vulnerable application. This can lead to full compromise of the application environment, including modification of application data, denial of service through resource exhaustion, and unauthorized actions. The vulnerability has a CVSS v3.1 base score of 8.9, indicating high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
An official security update is available that fixes this vulnerability in c3p0 version 0.12.0 and later. Users should upgrade to version 0.12.0 or newer to remediate the issue. The vendor advisory from Red Hat confirms the availability of this fix. If upgrading is not immediately possible, users should avoid resetting the userOverridesAsString property with untrusted data and review their use of c3p0 and mchange-commons-java to limit exposure. No vendor advisory states that no action is required or that the issue is already mitigated.
CVE-2026-27830: CWE-502: Deserialization of Untrusted Data in swaldman c3p0
Description
c3p0, a JDBC Connection pooling library, 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. 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. c3p0 additionally enforces the new mchange-commons-java `com.mchange.v2.naming.nameGuardClassName` to prevent injection of unexpected, potentially remote JNDI names. There is no supported workaround for versions of c3p0 prior to 0.12.0.
CVSS v4.0
Score 8.9high
Affected software
swaldman
c3p0
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The c3p0 library versions before 0.12.0 maintain the userOverridesAsString property as a hex-encoded serialized object representing a Map structure. An attacker able to manipulate this property, either on an existing ConnectionPoolDataSource or through crafted serialized objects or javax.naming.Reference instances, can cause the application to deserialize malicious data. This leads to arbitrary code execution on the application's CLASSPATH. The vulnerability is exacerbated by mchange-commons-java's early JNDI implementation that allows remote factoryClassLocation values, enabling attackers to cause the application to download and execute malicious code remotely. The vulnerability is tracked as CWE-502 (Deserialization of Untrusted Data) and CWE-94 (Code Injection).
Potential Impact
Successful exploitation allows an attacker with low privileges and adjacent network access to execute arbitrary code within the context of the vulnerable application. This can lead to full compromise of the application environment, including modification of application data, denial of service through resource exhaustion, and unauthorized actions. The vulnerability has a CVSS v3.1 base score of 8.9, indicating high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
An official security update is available that fixes this vulnerability in c3p0 version 0.12.0 and later. Users should upgrade to version 0.12.0 or newer to remediate the issue. The vendor advisory from Red Hat confirms the availability of this fix. If upgrading is not immediately possible, users should avoid resetting the userOverridesAsString property with untrusted data and review their use of c3p0 and mchange-commons-java to limit exposure. No vendor advisory states that no action is required or that the issue is already mitigated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-02-24T02:32:39.800Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-27830","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:18054","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:18055","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:28385","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:4285","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:18059","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:3890","vendor":"Red Hat"}]
Threat ID: 699f9a40b7ef31ef0b7260eb
Added to database: 02/26/2026, 00:56:32 UTC
Last enriched: 08/11/2026, 17:59:04 UTC
Last updated: 09/14/2026, 22:11:26 UTC
Views: 175
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