GHSA-5476-XC4J-RQCV

Vulnerability from github – Published: 2026-02-25 18:35 – Updated: 2026-02-25 18:35
VLAI?
Summary
c3p0 vulnerable to Remote Code Execution via unsafe deserialization of userOverridesAsString property
Details

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

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "com.mchange:c3p0"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.12.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27830"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502",
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-25T18:35:23Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nc3p0 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\u003cString,Map\u003cString,String\u003e\u003e`. 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\u0027s `CLASSPATH`.\n\nThe danger of this vulnerability was strongly magnified by vulnerabilities in c3p0\u0027s 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\u0027s `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`.\n\nAlthough hazard presented by c3p0\u0027s 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.\n\n### Patches\n\nThe `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.\n\nc3p0-0.12.0+ 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](https://www.mchange.com/projects/c3p0/#configuring_security).\n\nc3p0 additionally enforces the new mchange-commons-java `com.mchange.v2.naming.nameGuardClassName` to prevent injection of unexpected, potentially remote JNDI names.\n\n### Workarounds\n\nUsers should upgrade to c3p0-0.12.0 or above. There is no supported workaround for earlier versions of c3p0.\n\n### References\n\n[c3p0, you little rascal \u0026mdash; Hans-Martin M\u00fcnch](https://mogwailabs.de/en/blog/2025/02/c3p0-you-little-rascal/)\n[c3p0 documentation, security note](https://www.mchange.com/projects/c3p0/#security-note)\n[c3p0 documentation, configuring security](https://www.mchange.com/projects/c3p0/#configuring_security)",
  "id": "GHSA-5476-xc4j-rqcv",
  "modified": "2026-02-25T18:35:23Z",
  "published": "2026-02-25T18:35:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/swaldman/c3p0/security/advisories/GHSA-5476-xc4j-rqcv"
    },
    {
      "type": "WEB",
      "url": "https://github.com/swaldman/c3p0/commit/e14cbd8166e423e2e9a9d6f08b2add3433492d6e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/swaldman/c3p0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "c3p0 vulnerable to Remote Code Execution via unsafe deserialization of userOverridesAsString property"
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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