CVE-2026-71253
Apache Johnzon: ClassConverter loads & static-initializes an attacker-named class from untrusted JSON
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.8
Apache Johnzon: ClassConverter loads & static-initializes an attacker-named class from untrusted JSON
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.
- Record
CVE-2026-71253- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-470
- Updated
- 2026-11-02
EUVDEUVD-2026-104193
9.8
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.
- Record
EUVD-2026-104193- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-66gj-8qvf-qvfh
9.8
Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability...
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.
- Record
GHSA-66gj-8qvf-qvfh- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-470
- Updated
- 2026-11-02
NVD
9.8
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.
- Record
CVE-2026-71253- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-470
- Updated
- 2026-11-02
OSV
9.8
Apache Johnzon: ClassConverter loads & static-initializes an attacker-named class from untrusted JSON
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.
- Record
CVE-2026-71253- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-470
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-71253 is a critical vulnerability (CVSS 9.8) in Apache Software Foundation Johnzon, published October 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. No source names a fixed version.
References
github.com/apache/johnzon/commit/dd3d00634c746a2173a2518e882e85e8a151bf30
github.com/apache/johnzon/commit/91e7b0d21d08d138944e2570691939739422a3d6
lists.apache.org/thread.html/3vgm1yo2sn9yhkvvs9lc4ro01vl3zt68
nvd.nist.gov/vuln/detail/CVE-2026-71253
github.com/advisories/GHSA-66gj-8qvf-qvfh
repo.maven.apache.org/maven2
github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71253.json