CVE-2016-4000

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 12.5%, top 6% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 7%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
93.0%
KEV
Not listed

Published

July 6, 2017

Last Modified

May 13, 2026

Advisory Details (8)

Auto-updated May 16, 2026
Patch available.
generic

Jython: Arbitrary code execution (GLSA 201710-28) — Gentoo security

https://security.gentoo.org/glsa/201710-28
generic

CVE-2016-4000

https://security-tracker.debian.org/tracker/CVE-2016-4000
generic
https://lists.apache.org/thread.html/0919ec1db20b1022f22b8e78f355667df74d6142b463ff17d03ad533%40%3Cdevnull.infra.apache.org%3E
generic
https://hg.python.org/jython/rev/d06e29d100c0
generic Patch Available

#864859 - jython: CVE-2016-4000: Unsafe deserialization leads to code execution - Debian Bug report logs

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=864859
generic
http://www.securityfocus.com/bid/105647
generic

[SECURITY] [DSA 3893-1] jython security update

http://www.debian.org/security/2017/dsa-3893
generic

Issue 2454: Security Vulnerability in Jython - Jython tracker

http://bugs.jython.org/issue2454

Vendor Advisories for CVE-2016-4000(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
Maven(2)
PackageVulnerable rangeFixed inDependents
org.python:jython2.2 ... 2.7.1b3 (21 versions)2.7.1-rc1—
org.python:jython-standalone2.5.1 ... 2.7.1b3 (18 versions)2.7.1—

Data Freshness Timeline

(refreshed 9× in last 7d / 42× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-07 13:42 UTCEPSS rescore
  2. 2026-07-06 16:24 UTCEPSS rescore
  3. 2026-07-06 16:24 UTCEPSS rescore
  4. 2026-07-06 02:20 UTCEPSS rescore
  5. 2026-07-06 02:20 UTCEPSS rescore
  6. 2026-07-05 02:27 UTCEPSS rescore
  7. 2026-07-04 06:28 UTCEPSS rescore
  8. 2026-07-01 15:02 UTCEPSS rescore
  9. 2026-06-30 23:19 UTCEPSS rescore
  10. 2026-06-29 14:03 UTCEPSS rescore
  11. 2026-06-28 14:04 UTCEPSS rescore
  12. 2026-06-28 04:53 UTCEPSS rescore
  13. 2026-06-27 03:05 UTCEPSS rescore
  14. 2026-06-27 03:05 UTCEPSS rescore
  15. 2026-06-25 13:47 UTCEPSS rescore
  16. 2026-06-25 13:47 UTCEPSS rescore
  17. 2026-06-24 14:02 UTCEPSS rescore
  18. 2026-06-24 14:02 UTCEPSS rescore
  19. 2026-06-23 21:30 UTCEPSS rescore
  20. 2026-06-22 14:23 UTCEPSS rescore
  21. 2026-06-21 14:54 UTCEPSS rescore
  22. 2026-06-21 14:54 UTCEPSS rescore
  23. 2026-06-19 19:23 UTCEPSS rescore
  24. 2026-06-19 19:23 UTCEPSS rescore
  25. 2026-06-19 17:55 UTCOSV refresh
Show 59 more
  1. 2026-06-18 17:50 UTCEPSS rescore
  2. 2026-06-17 17:50 UTCEPSS rescore
  3. 2026-06-17 17:50 UTCEPSS rescore
  4. 2026-06-16 17:50 UTCEPSS rescore
  5. 2026-06-16 17:50 UTCEPSS rescore
  6. 2026-06-15 17:45 UTCEPSS rescore
  7. 2026-06-14 23:14 UTCEPSS rescore
  8. 2026-06-13 22:57 UTCEPSS rescore
  9. 2026-06-13 22:57 UTCEPSS rescore
  10. 2026-06-12 23:09 UTCEPSS rescore
  11. 2026-06-12 23:09 UTCEPSS rescore
  12. 2026-06-11 13:57 UTCEPSS rescore
  13. 2026-06-10 22:15 UTCEPSS rescore
  14. 2026-06-10 13:18 UTCEPSS rescore
  15. 2026-06-08 14:14 UTCEPSS rescore
  16. 2026-06-07 15:22 UTCEPSS rescore
  17. 2026-06-07 15:22 UTCEPSS rescore
  18. 2026-06-06 13:45 UTCEPSS rescore
  19. 2026-06-05 22:44 UTCEPSS rescore
  20. 2026-06-05 06:08 UTCEPSS rescore
  21. 2026-06-05 06:08 UTCEPSS rescore
  22. 2026-06-04 13:10 UTCEPSS rescore
  23. 2026-06-04 13:10 UTCEPSS rescore
  24. 2026-06-02 20:10 UTCEPSS rescore
  25. 2026-06-01 13:49 UTCEPSS rescore
  26. 2026-06-01 13:49 UTCEPSS rescore
  27. 2026-05-31 22:28 UTCEPSS rescore
  28. 2026-05-31 22:28 UTCEPSS rescore
  29. 2026-05-31 00:14 UTCEPSS rescore
  30. 2026-05-30 23:23 UTCOSV refresh
  31. 2026-05-29 13:41 UTCEPSS rescore
  32. 2026-05-28 13:42 UTCEPSS rescore
  33. 2026-05-28 13:42 UTCEPSS rescore
  34. 2026-05-27 13:38 UTCEPSS rescore
  35. 2026-05-27 13:38 UTCEPSS rescore
  36. 2026-05-26 13:42 UTCEPSS rescore
  37. 2026-05-26 07:16 UTCEPSS rescore
  38. 2026-05-24 16:43 UTCEPSS rescore
  39. 2026-05-23 00:10 UTCEG score recompute
  40. 2026-05-22 21:15 UTCEPSS rescore
  41. 2026-05-22 21:15 UTCEPSS rescore
  42. 2026-05-21 22:40 UTCEPSS rescore
  43. 2026-05-20 22:37 UTCEPSS rescore
  44. 2026-05-20 22:37 UTCEPSS rescore
  45. 2026-05-20 22:37 UTCEPSS rescore
  46. 2026-05-20 11:21 UTCEPSS rescore
  47. 2026-05-20 11:21 UTCEPSS rescore
  48. 2026-05-20 11:21 UTCEPSS rescore
  49. 2026-05-20 09:17 UTCEG score recompute
  50. 2026-05-20 04:59 UTCEG score recompute
  51. 2026-05-20 00:41 UTCEG score recompute
  52. 2026-05-19 20:23 UTCEG score recompute
  53. 2026-05-19 16:05 UTCEG score recompute
  54. 2026-05-19 11:47 UTCEG score recompute
  55. 2026-05-19 07:29 UTCEG score recompute
  56. 2026-05-19 03:11 UTCEG score recompute
  57. 2026-05-18 22:54 UTCEG score recompute
  58. 2026-05-18 21:30 UTCEPSS rescore
  59. 2026-05-18 21:30 UTCEPSS rescore

Frequently asked(5)

What is CVE-2016-4000?
CVE-2016-4000 is a critical vulnerability published on July 6, 2017. Jython before 2.7.1rc1 allows attackers to execute arbitrary code via a crafted serialized PyFunction object.
When was CVE-2016-4000 disclosed?
CVE-2016-4000 was first published in the National Vulnerability Database on July 6, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-4000 actively exploited?
CVE-2016-4000 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-4000?
CVE-2016-4000 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2016-4000?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-4000, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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