CVE-2026-54513
Received Received - Intake
Type Confusion in Jackson Databind

Publication date: 2026-06-23

Last updated on: 2026-06-23

Assigner: GitHub, Inc.

Description
jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.10.0 until 2.18.8, 2.21.4, and 3.1.4, BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-06-23
Last Modified
2026-06-23
Generated
2026-06-24
AI Q&A
2026-06-24
EPSS Evaluated
N/A
NVD
CVE-2026-54513
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
jackson jackson-databind From 2.10.0 (inc) to 2.18.8 (exc)
jackson jackson-databind 2.18.8
jackson jackson-databind 2.21.4
jackson jackson-databind 3.1.4
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-184 The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

The vulnerability exists in jackson-databind's BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() method. This method allowlists any array type based solely on whether the class is an array, without validating the array's component (element) type against the configured allowlist.

As a result, even if there is an explicit allowlist of concrete types, an array of a disallowed type (e.g., EvilType[]) can still be deserialized. When Jackson deserializes such arrays and no per-element type IDs are present, it directly instantiates the component type without further checks, effectively bypassing the allowlist.

This flaw allows potentially unsafe types to be deserialized, which can lead to security issues.

Impact Analysis

This vulnerability can lead to the deserialization of unauthorized or malicious types, which may result in remote code execution or other severe security impacts.

Because the vulnerability allows instantiation of disallowed types, attackers could exploit it to execute arbitrary code, compromise data integrity, or cause denial of service.

The CVSS score of 8.1 indicates a high severity with impacts on confidentiality, integrity, and availability.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade jackson-databind to one of the fixed versions: 2.18.8, 2.21.4, or 3.1.4.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-54513. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart