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VulnerabilityPublished Updated

CVE-2026-27830: swaldman c3p0 · Deserialization of Untrusted Data

Affects swaldman c3p0Source CVE Database V5

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Not known to be exploited · CVSS 8.9 High : upgrade to 0.12.0 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score
8.9High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 0.12.0
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 26 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade c3p0 and com.mchange/c3p0 to 0.12.0.

Affected software

ProductAffectedFixed in
swaldmanc3p0Affected
  • <0.12.0
Fixed in
  • 0.12.0
Mavencom.mchange/c3p0pkg:maven/com.mchange/c3p0Other threatsAffected
  • <0.12.0
Fixed in
  • 0.12.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

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.

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.

References

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