Objenesis before 3.6 contains a type confusion vulnerability that allows code in one class loader to substitute
Source GCVE Database
Not known to be exploited · CVSS 2.0 Low : upgrade to 3.6 when convenient.
Data as of 26 Oct 2026, 16:50 UTC
- Patch
- Available – fixed in 3.6
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade objenesis and easymock/objenesis to 3.6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| easymockobjenesis | Affected
| Fixed in
|
Maveneasymock/objenesispkg:maven/easymock/objenesisOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, avoid sharing ObjenesisStd instances across class loaders or isolate class loader usage to prevent instantiator caching collisions.
Description
Objenesis versions before 3.6 have a type confusion vulnerability due to instantiator caching keyed on class name, which can cause objects from one class loader to be substituted for those of another. This leads to ClassCastException failures when newInstance() returns objects of the wrong class.
References
- github.com/easymock/objenesis/security/advisories/GHSA-743r-26gf-97ff (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-116486 (opens in a new tab)
- github.com/easymock/objenesis/commit/40f90f435a06b16af74a7398f0007faeaa52c00c (opens in a new tab)
- github.com/easymock/objenesis (opens in a new tab)
- github.com/easymock/objenesis/blob/fb36e5c377ed1bf57a18386fa79d2eed4ddfcfac/main/src/main/java/org/objenesis/ObjenesisBase.java (opens in a new tab)
- vulncheck.com/advisories/objenesis-before-3.6-type-confusion-via-class-name-instantiator-cache (opens in a new tab)