CVE-2026-54515: jackson-databind: Case-insensitive deserialization bypasses per-property @JsonIgnoreProperties

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 2.8.0 until 2.18.9, 2.21.5, and 3.1.4, in BeanDeserializerBase.createContextual(), per-property @JsonIgnoreProperties exclusions are applied by _handleByNameInclusion(), producing a contextual deserializer whose BeanPropertyMap has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds from this._beanProperties (the original, unfiltered map) instead of contextual._beanProperties, then overwrites the filtered map — restoring every property _handleByNameInclusion had just removed. The ignored property becomes writable again. This vulnerability is fixed in 2.18.9, 2.21.5, and 3.1.4.

Affected products

FasterXML jackson-databind: from 2.8.0 before 2.18.9; from 2.19.0 before 2.21.5; from 3.0.0 before 3.1.4; 2.22.0 — fixed in 2.18.9, 2.21.5, 3.1.4
Maven Com.Fasterxml.Jackson.Core:Jackson-Databind: from 3.1.0 before 3.1.4; from 2.8.0 before 2.18.9; from 2.19.0 before 2.21.5; from 2.22.0 before 2.22.1; 2.10.0, 2.10.0.pr1, 2.10.0.pr2, 2.10.0.pr3, 2.10.1, 2.10.2 (+129) — fixed in 3.1.4, 2.18.9, 2.21.5, 2.22.1
Maven Tools.Jackson.Core:Jackson-Databind: from 3.1.0 before 3.1.4; 3.1.0, 3.1.1, 3.1.2, 3.1.3 — fixed in 3.1.4

How to fix

Upgrade to a fixed version: FasterXML jackson-databind 2.18.9, 2.21.5, 3.1.4; Maven Com.Fasterxml.Jackson.Core:Jackson-Databind 3.1.4, 2.18.9, 2.21.5, 2.22.1; Maven Tools.Jackson.Core:Jackson-Databind 3.1.4. Check the vendor advisory for mitigations.

References

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