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CVE Record

CVE-2026-54513: jackson-databind: Array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray)

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.

HighCVSS 8.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a high-severity flaw in Jackson Databind used by Java applications. A specific safety allowlist for polymorphic deserialization can be bypassed for array types, allowing an otherwise disallowed element class to be instantiated. Exposure depends on application configuration and untrusted input paths, not simply having Jackson present.

Executive priority

Prioritize remediation for internet-facing or partner-facing Java services that deserialize untrusted data. The issue has high impact potential, but exposure is configuration-specific and no active exploitation is cited in the provided sources.

Technical view

BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() accepts any array using clazz.isArray() without checking the component type against the configured allowlist. In affected versions, deserialization may instantiate a non-allowlisted array component type when elements lack per-element type IDs, bypassing intended subtype controls.

Likely exposure

Likely exposure is Java software using affected jackson-databind versions with polymorphic deserialization, BasicPolymorphicTypeValidator, allowIfSubTypeIsArray(), and externally controlled serialized input. Standard data binding without this validator pattern is not confirmed exposed by the provided sources.

Exploitation context

The CVSS vector is network-accessible with no privileges or user interaction, but high attack complexity. The source bundle does not identify active exploitation, and KEV status is false. Practical exploitability depends on reachable deserialization paths and available dangerous application classes.

Researcher notes

Focus triage on the combination of affected versions, polymorphic deserialization, allowIfSubTypeIsArray(), and explicit concrete-type allowlists. The bypass concerns array component validation, not a blanket vulnerability in every Jackson Databind deployment.

Mitigation direction

  • Upgrade jackson-databind to 2.18.8, 2.21.4, or 3.1.4 as applicable.
  • Check vendor advisories for backported fixes in packaged distributions.
  • Inventory direct and transitive jackson-databind dependencies across Java services.
  • Review use of BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray().
  • Reduce or remove polymorphic deserialization of untrusted input where feasible.

Validation and detection

  • Confirm deployed jackson-databind versions are outside the affected ranges.
  • Search code for allowIfSubTypeIsArray and BasicPolymorphicTypeValidator usage.
  • Map endpoints, queues, or jobs that deserialize externally supplied data.
  • Verify dependency resolution after builds, including shaded or bundled libraries.
  • Track Red Hat or vendor package status where Jackson is supplied by the platform.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-184: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-54513 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.1 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
11Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.1CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9GitHub_M
8.1CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

8.1High
CVSS 3.1 vector shape for CVE-2026-54513Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPjackson-databind: Jackson-databind: Security bypass allows arbitrary code execution
other:Red Hat severity ratingcvssV3_1
  • 2026-06-23T22:01:34.437Z: Reported to Red Hat.
  • 2026-06-23T20:53:52.543Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
FasterXMLjackson-databind>= 2.10.0, < 2.18.8, >= 2.19.0, < 2.21.4, >= 3.0.0, < 3.1.4Listed
Weakness

CWE details

CWE-184

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-184 · source CWE mapping

Incomplete List of Disallowed Inputs

Incomplete List of Disallowed Inputs represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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