Deserialization of Untrusted Data Affecting tools.jackson.core:jackson-databind package, versions [3.0.0, 3.1.8)[3.2.0, 3.2.4)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published28 Oct 2026
- disclosed28 Oct 2026
- creditAdamKorcz, Ada Logics, François Martin
Introduced: 28 Oct 2026
NewCVE-2026-110879 (opens in a new tab)How to fix?
Upgrade tools.jackson.core:jackson-databind to version 3.1.8, 3.2.4 or higher.
Overview
Affected versions of this package are vulnerable to Deserialization of Untrusted Data in the _resolveAndValidateGeneric() and _validateTypeParameter() methods of the DatabindContext class. An attacker can instantiate arbitrary classes by supplying a class-name type ID whose generic arguments or array element type name a class that is not validated, because only the outer type is checked against the PolymorphicTypeValidator. Exploitation requires deserializing untrusted JSON with class-name type IDs, through annotation-based polymorphism or default typing, where the outer base type is approved, and a usable gadget class is on the classpath.
Workaround
This vulnerability can be avoided by using narrow subtype rules, preventing attackers from writing serialized cache or session values, or removing unnecessary dependencies that provide gadget classes.
Note: This is a bypass of the fix for the vulnerability described in CVE-2026-54512.
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.