Junglewise Threat Intelligence

FasterXML jackson-databind JsonView bypass in creator properties

Severity: medium · CVSS 6.5 · Published 2026-07-21

Executive brief

A security bypass exists in the Jackson data processing library, which is widely used in Java applications to handle data exchange. Under specific configurations, an attacker can submit data to fields that are supposed to be restricted or hidden, such as administrative settings or internal metadata. This could allow unauthorized users to modify sensitive data or bypass access controls in web applications that rely on Jackson for data validation.

Technical details

An authorization bypass (CWE-863) exists in BeanDeserializer.java within the deserializeUsingPropertyBasedWithExternalTypeId method. The vulnerability occurs because the creator-property branch fails to perform a visibility check using visibleInView(activeView), unlike the regular bean-property branch. An attacker can exploit this by providing JSON input that targets a constructor parameter annotated with both @JsonView and @JsonTypeInfo(include=As.EXTERNAL_PROPERTY). This allows the population of restricted fields even when a more restrictive view is active. The issue is a patch gap where a fix in the 3.x line was not backported to the 2.18 and 2.21 branches. Patches are available in versions 2.18.9 and 2.21.5.

Affected products

  • FasterXML jackson-databind >= 2.18.0, <= 2.18.8
  • FasterXML jackson-databind >= 2.21.0, <= 2.21.4

Timeline

  • 2026-05-22: other: Fix committed to 3.x branch
  • 2026-07-10: disclosed: Advisory published by maintainer
  • 2026-07-21: advisory: GitHub Advisory Database entry reviewed

References

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