CVE-2026-71253

Apache Johnzon: ClassConverter loads & static-initializes an attacker-named class from untrusted JSON

State: Published
Severity: 9.8 Critical
Published: Oct 19, 2026
Updated: Oct 20, 2026
Reserved: Aug 5, 2026

Description

Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability in Apache Johnzon.

ClassConverter loads & static-initializes an attacker-named class from untrusted JSON.

This issue affects Apache Johnzon: from 1.0.0 before 2.2.0.

Users are recommended to upgrade to version 1.3.1 (javax namespace) or 2.2.0 (jakarta specification namespace), which fixes the issue.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-470 Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')

Affected Products

Product	Versions
Apache JohnzonApache Software Foundation	2.0.0 to before 2.2.0Affected 1.0.0 to before 1.3.1Affected

References

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