CVE-2026-54516Public exploitNetwork attack vector

Ignored-field writes via renamed property backing fields

Published Jun 23, 2026 · Updated Jun 23, 2026

Improper object modification in jackson-databind 2.21.0 through 2.21.3 and 3.0.0 through 3.1.3 allows remote attackers to write ignored fields. POJOPropertiesCollector._renameProperties() retains a private backing field when a getter is renamed and its setter is ignored, so BeanDeserializerFactory.addBeanProps() creates a writable FieldProperty for the attacker-controlled key. Exploitation requires an application to deserialize attacker-supplied JSON into this annotated property while the default INFER_PROPERTY_MUTATORS setting is enabled; the result is an unauthorized write to the backing field.

CVSS severity5.3
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper object modification in jackson-databind 2.21.0 through 2.21.3 and 3.0.0 through 3.1.3 allows remote attackers to write ignored fields. POJOPropertiesCollector._renameProperties() retains a private backing field when a getter is renamed and its setter is ignored, so BeanDeserializerFactory.addBeanProps() creates a writable FieldProperty for the attacker-controlled key. Exploitation requires an application to deserialize attacker-supplied JSON into this annotated property while the default INFER_PROPERTY_MUTATORS setting is enabled; the result is an unauthorized write to the backing field.

The record

CVE
CVE-2026-54516
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
FasterXML
Product
jackson-databind
Classifications
CWE-915
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.21.0, < 2.21.4
  2. Affected versionversion=>= 3.0.0, < 3.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FasterXML · jackson-databindversion=>= 2.21.0, < 2.21.4; version=>= 3.0.0, < 3.1.4

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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