CVE-2026-59889 FasterXML CVE debrief

Who should care

Developers and security teams using jackson-databind versions between 2.18.0 and 2.18.8, 2.21.4 and earlier, 2.22.0, 3.1.4 and earlier, and 3.2.0 should prioritize patching. This includes reviewing and updating inventory for affected versions and implementing compensating controls for JSON deserialization.

Technical summary

CVE-2026-59889 is a vulnerability in jackson-databind's UnwrappedPropertyHandler. From versions 2.18.0 until 2.18.9, 2.21.5, 2.22.1, 3.1.5, and 3.2.1, the processUnwrapped() method replays buffered JSON for a @JsonUnwrapped property and calls prop.deserializeAndSet() without a prop.visibleInView(ctxt.getActiveView()) guard. This allows a property annotated with both @JsonView and @JsonUnwrapped to be written from attacker JSON under a less-privileged active view. The vulnerability can be mitigated by applying patches for affected versions.

Defensive priority

Apply patches for jackson-databind versions 2.18.9, 2.21.5, 2.22.1, 3.1.5, and 3.2.1. Review and update inventory for affected versions. Monitor for suspicious JSON input and implement compensating controls for JSON deserialization.

Recommended defensive actions

• Apply patches for jackson-databind versions 2.18.9, 2.21.5, 2.22.1, 3.1.5, and 3.2.1
• Review and update inventory for affected versions
• Monitor for suspicious JSON input
• Implement compensating controls for JSON deserialization
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

The CVE record was published on 2026-07-14T21:17:06.160Z and was last modified on 2026-07-16T16:19:15.790Z. The NVD entry is currently Awaiting Analysis. This information is based on the CVE record and NVD entry. Further verification is recommended.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.