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Fencer Intel
critical 9.8

CVE-2016-4000 json

Deserialization of Untrusted Data in Jython

published 2017-07-06 9 y ago modified 2026-07-02 4 mo ago also GHSA-6r7r-jj8h-pq6v , EUVD-2022-2855

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.2%
EPSS 6.2% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

Jython before 2.7.1rc1 allows attackers to execute arbitrary code via a crafted serialized PyFunction object.

Patch / fix

  • maven org.python:jython-standalone 2.7.1b3
  • maven org.python:jython 2.7.1b3
  • jython Debian 14, Debian 13, Debian 12 2.5.3-17

debian advisories DEBIAN-CVE-2016-4000

  • jython Ubuntu 14.04 LTS 2.5.3-1ubuntu0.1
  • jython Ubuntu 16.04 LTS 2.5.3-9ubuntu0.1

ubuntu advisories UBUNTU-CVE-2016-4000

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2016-4000 updated cvss 8.1

jython: Unsafe deserialization leads to code execution

  • Red Hat JBoss Fuse Service Works 6 jython Red Hat JBoss SOA Platform 5 jython
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 jython, jython-demo, jython-manual, jython-javadoc Red Hat OpenShift Enterprise 2 jython Red Hat Software Collections rh-eclipse46-jython, rh-eclipse46-jython-demo, rh-eclipse46-jython-manual, rh-eclipse46-jython-javadoc
    not affected: vulnerable code not present

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

Exploit prediction

6.21% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.python:jython-standalone
<2.7.1b3
2.7.1b3
maven org.python:jython
<2.7.1b3
2.7.1b3

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Intel 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.