Improperly Controlled Modification of Dynamically-Determined Object Attributes Affecting com.fasterxml.jackson.core:jackson-databind package, versions [2.21.0,2.21.4)
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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- published25 Jun 2026
- disclosed23 Jun 2026
- creditOmkhar Arasaratnam
Introduced: 23 Jun 2026
NewCVE-2026-54516 (opens in a new tab)How to fix?
Upgrade com.fasterxml.jackson.core:jackson-databind to version 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 Improperly Controlled Modification of Dynamically-Determined Object Attributes in the POJOPropertiesCollector._renameProperties() and BeanDeserializerFactory.addBeanProps() methods, which rename rather than drop a property whose getter carries @JsonProperty and whose setter carries @JsonIgnore, leaving the private backing field writable. An attacker can write a field that was meant to be unsettable, enabling property tampering and mass assignment, by supplying the renamed JSON key during deserialization, because the factory observes hasField()==true and builds a writable FieldProperty for the backing field. Exploitation requires MapperFeature.INFER_PROPERTY_MUTATORS to be enabled, which is the default, and a target type that pairs a renamed getter with an ignored setter, and the impact is limited to writing existing fields with no path to remote code execution.