CVE-2026-59888: FasterXML jackson-databind @JsonIgnore bypass in Java Records

CVE-2026-59888 · Severity: medium · CVSS 6.5 · Published 2026-07-14

A vulnerability in the Jackson data-processing library allows attackers to bypass security restrictions on Java Records. Specifically, internal data fields that were intended to be hidden or ignored can be modified by an external user if a custom naming strategy is used. This could allow an attacker to change sensitive information, such as user roles or administrative flags, that should not be accessible from the network.

Technologies: FasterXML Jackson Databind, com.fasterxml.jackson.core:jackson-databind (Maven), tools.jackson.core:jackson-databind (Maven). Vendors: FasterXML, Maven.

Quick answers

Is CVE-2026-59888 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-59888 being exploited in the wild.
How severe is CVE-2026-59888?
Medium severity, with a CVSS score of 6.5, published 14 July 2026.
Which products and versions are affected?
FasterXML Jackson Databind >= 2.15.0, < 2.18.8, >= 2.15.0, < 2.18.8; >= 2.19.0, < 2.21.4; >= 3.0.0, < 3.1.4; com.fasterxml.jackson.core:jackson-databind (Maven) ECOSYSTEM:introduced=2.15.0,fixed=2.18.8; tools.jackson.core:jackson-databind (Maven) ECOSYSTEM:introduced=3.0.0,fixed=3.1.4.
Is there a fix for CVE-2026-59888?
Yes. com.fasterxml.jackson.core:jackson-databind (Maven): upgrade to 2.18.8 or later; tools.jackson.core:jackson-databind (Maven): upgrade to 3.1.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-59888 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-59888?
Check whether you run FasterXML Jackson Databind, com.fasterxml.jackson.core:jackson-databind (Maven) or tools.jackson.core:jackson-databind (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • com.fasterxml.jackson.core:jackson-databind (Maven): upgrade to 2.18.8 or later
    # set com.fasterxml.jackson.core:jackson-databind to 2.18.8 in your pom.xml or build.gradle
  • tools.jackson.core:jackson-databind (Maven): upgrade to 3.1.4 or later
    # set tools.jackson.core:jackson-databind to 3.1.4 in your pom.xml or build.gradle

Technical details

A vulnerability in jackson-databind occurs when processing Java Records using a PropertyNamingStrategy. The POJOPropertiesCollector._removeUnwantedIgnorals() method records @JsonIgnore-annotated components using their original implicit names before the naming strategy is applied via _renameUsing(). Consequently, the internal list of ignored properties contains stale names, allowing the renamed JSON keys to bypass IgnorePropertiesUtil.shouldIgnore(). An attacker can exploit this to perform mass assignment on sensitive Record fields that were intended to be ignored during deserialization. The issue is fixed in versions 2.18.8, 2.21.4, and 3.1.4.

Affected products

  • FasterXML jackson-databind >= 2.15.0, < 2.18.8
  • FasterXML jackson-databind >= 2.19.0, < 2.21.4
  • tools.jackson.core:jackson-databind jackson-databind >= 3.0.0, < 3.1.4

Identifiers

  • CVE-2026-59888
  • GHSA-3pjw-73gf-8qr5

Timeline

  • 2026-07-10: disclosed: Initial disclosure to maintainers
  • 2026-07-14: advisory: NVD publication date
  • 2026-07-21: advisory: GitHub Advisory published

References

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