---
id: CVE-2026-116486
title: Objenesis before 3.6 Type Confusion via Class Name Instantiator Cache
summary: >-
  Objenesis before 3.6 contains a type confusion vulnerability that allows code
  in one class loader to substitute objects into another by exploiting
  instantiator caching keyed on class name. When a shared ObjenesisStd instance
  caches insta…
severity: medium
cvss: 4.5
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-386
vendor: easymock
product: objenesis
affected:
  - objenesis < 3.6
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-26T15:38:10.344457Z'
published: '2026-10-26'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T16:15:59.231Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116486'
references:
  - url: >-
      https://github.com/easymock/objenesis/commit/40f90f435a06b16af74a7398f0007faeaa52c00c
    label: Patch Commit
  - url: >-
      https://github.com/easymock/objenesis/security/advisories/GHSA-743r-26gf-97ff
    label: GitHub Security Advisory (GHSA-743r-26gf-97ff)
  - url: >-
      https://github.com/easymock/objenesis/blob/fb36e5c377ed1bf57a18386fa79d2eed4ddfcfac/main/src/main/java/org/objenesis/ObjenesisBase.java#L92-L95
  - url: 'https://github.com/easymock/objenesis'
  - url: >-
      https://www.vulncheck.com/advisories/objenesis-before-3.6-type-confusion-via-class-name-instantiator-cache
    label: >-
      VulnCheck Advisory: Objenesis before 3.6 Type Confusion via Class Name
      Instantiator Cache
tags:
  - cve.org
ingestedAt: '2026-10-26T14:27:31.827Z'
---

## Overview

Objenesis before 3.6 contains a type confusion vulnerability that allows code in one class loader to substitute objects into another by exploiting instantiator caching keyed on class name. When a shared ObjenesisStd instance caches instantiators by clazz.getName() in ObjenesisBase.getInstantiatorOf(), same-named classes collide, causing newInstance() to return wrong-class objects and ClassCastException failures.

## Affected

- `objenesis < 3.6`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.