CVE-2026-54516: jackson-databind: Renamed @JsonIgnore'd setters can deserialize via private fields

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-23 · updated 2026-10-25
Weakness: CWE-915

Description

jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.21.0 until 2.21.4 and 3.1.4, POJOPropertiesCollector._renameProperties() allows a property with @JsonProperty("renamed") on the getter and @JsonIgnore on the setter to be renamed rather than dropped. With MapperFeature.INFER_PROPERTY_MUTATORS enabled (default), the private backing field is retained; during deserialization BeanDeserializerFactory.addBeanProps() sees hasField()==true, builds a FieldProperty, and makes the backing field writable. An attacker supplying the renamed JSON key writes the backing field directly, bypassing the @JsonIgnore on the setter. This vulnerability is fixed in 3.1.4.

Affected products

FasterXML jackson-databind: from 2.21.0 before 2.21.4; from 3.0.0 before 3.1.4 — fixed in 2.21.4, 3.1.4

How to fix

Upgrade to a fixed version: FasterXML jackson-databind 2.21.4, 3.1.4. Check the vendor advisory for mitigations.

References

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