Deserialization of Untrusted Data Affecting com.fasterxml.jackson.core:jackson-databind package, versions [2.10.0,2.18.8)[2.19.0,2.21.4)
Threat Intelligence
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Test your applications- Snyk IDSNYK-JAVA-COMFASTERXMLJACKSONCORE-17440598
- published24 Jun 2026
- disclosed23 Jun 2026
- creditcaveeroo,Omkhar Arasaratnam
Introduced: 23 Jun 2026
NewCVE-2026-54512 (opens in a new tab)How to fix?
Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.8, 2.21.4 or higher.
Overview
com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.
Affected versions of this package are vulnerable to Deserialization of Untrusted Data in the DatabindContext._resolveAndValidateGeneric() method, which validates only the raw container class of a type identifier against the configured PolymorphicTypeValidator and not its nested generic type arguments. An attacker who controls the type identifier can instantiate a denied class, and reach unauthenticated remote code execution through an available gadget, by embedding that class as a generic parameter of an allowlisted container such as java.util.ArrayList<com.evil.Gadget>, which passes validation while the nested type is loaded, instantiated, and populated with attacker-controlled values. Exploitation requires polymorphic type validation to be enabled with a configured validator, the application to deserialize untrusted JSON, and a suitable gadget class on the classpath.
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.