jackson-databind has case-insensitive deserialization bypasses per-property @JsonIgnoreProperties
Moderate severity
GitHub Reviewed
Published
Jun 16, 2026
in
FasterXML/jackson-databind
•
Updated Jul 16, 2026
Description
Published by the National Vulnerability Database
Jun 23, 2026
Published to the GitHub Advisory Database
Jun 23, 2026
Reviewed
Jun 23, 2026
Last updated
Jul 16, 2026
Summary
In
BeanDeserializerBase.createContextual(), per-property@JsonIgnorePropertiesexclusions are applied by_handleByNameInclusion(), producing acontextualdeserializer whoseBeanPropertyMaphas the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by@JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds fromthis._beanProperties(the original, unfiltered map) instead ofcontextual._beanProperties, then overwrites the filtered map — restoring every property_handleByNameInclusionhad just removed. The ignored property becomes writable again.Impact
An application that both enables case-insensitive matching and relies on per-property
@JsonIgnorePropertiesto keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write).Affected / Patched
Will be fixed in 2.18.9, 2.21.5, 2.22.1 and 3.1.4.
Severity / CWE
Maintainer: minor. Reporter: Moderate. CWE-915.
Upstream fix
FasterXML/jackson-databind#5962 (PR #5964,
0e1b0b2), milestone 3.1.4. Released 2026-06-04.References