Vulnerability Report

CVE-2026-54513

Title: Polymorphic type validator bypass via array component type

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-54513.

CWE Category CWE-184

Published Date Jun 23, 2026

Modified Date Jul 23, 2026

Exploit Status Not Found

Score 8.1 CVSS v3.1

Exploit Probability (EPSS)

0.71%

Vulnerability Summary

CVE-2026-54513: 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.

Impacted Vendors

fasterxml 1

Reference Links

https://github.com/FasterXML/jackson-databind/commit/01d1692c8d0ed03e51a0e3c4f8a9e6908e4931e5 https://github.com/FasterXML/jackson-databind/commit/24529da29fdf46ff94ca38de9ebf31cd188f5e8e https://github.com/FasterXML/jackson-databind/issues/5981 https://github.com/FasterXML/jackson-databind/issues/5983 https://github.com/FasterXML/jackson-databind/pull/5984 https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-rmj7-2vxq-3g9f

CVSS v3.1

Source Entity [email protected]

Severity HIGH

8.1

Attack Vector

NETWORK

Complexity

HIGH

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H