CVE-2026-71253
Published:October 19, 2026
Updated:October 22, 2026
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.
Affected Packages
https://github.com/apache/johnzon.git (GITHUB):
Affected version(s) >=v1.0.0 <v1.3.1Fix Suggestion:
Update to version v1.3.1https://github.com/apache/johnzon.git (GITHUB):
Affected version(s) >=v2.0.0 <v2.2.0Fix Suggestion:
Update to version v2.2.0org.apache.johnzon:johnzon-mapper (JAVA):
Affected version(s) >=1.0.0 <1.3.1Fix Suggestion:
Update to version 1.3.1org.apache.johnzon:johnzon-mapper (JAVA):
Affected version(s) >=2.0.0 <2.2.0Fix Suggestion:
Update to version 2.2.0Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
EPSS
Base Score:
0.65