CVE-2026-71253 json
Apache Johnzon: ClassConverter loads & static-initializes an attacker-named class from untrusted JSON
published 2026-10-19 21 d ago modified 2026-10-20 19 d ago also EUVD-2026-104193
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Apache Software Foundation Apache Johnzon 1.3.1, 2.2.0
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-71253 updated cvss 8.1
org.apache.johnzon/johnzon-mapper: Apache Johnzon: Arbitrary code execution via unsafe class loading
-
Red Hat Fuse 7 johnzon-mapper 1.1.10affected: workaround, no fix planned “Out of support scope”
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 19 d ago
Exploit prediction
0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Apache Software Foundation Apache Johnzon
Classification
- Weakness
-
- CWE-470 Use of Externally-Controlled Input to Select Classes or Code
References
Sources
- CVE List CVE-2026-71253
- NVD CVE-2026-71253
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.