Description
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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| easymock | objenesis | < 3.6 | 3.6 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | objenesis | 3.6-1 | — |
| Debian 13 | objenesis | No fix yet | — |
| Debian 12 | objenesis | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | objenesis | No fix yet | — |
| Ubuntu 26.04 LTS | objenesis | No fix yet | — |
| Ubuntu 24.04 LTS | objenesis | No fix yet | — |
| Ubuntu 22.04 LTS | objenesis | No fix yet | — |
| Ubuntu 20.04 LTS | objenesis | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | objenesis | No fix yet | — |
| Ubuntu 16.04 LTS | objenesis | No fix yet | — |
| Ubuntu 14.04 LTS | objenesis | No fix yet | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | objenesis +1 | No fix yet | — |
References
- Patch Commit patch
- GitHub Security Advisory (GHSA-743r-26gf-97ff) vendor-advisory
- https://github.com/easymock/objenesis/blob/fb36e5c377ed1bf57a18386fa79d2eed4ddfcfac/main/src/main/java/org/objenesis/ObjenesisBase.java#L92-L95 technical-description
- https://github.com/easymock/objenesis product
- VulnCheck Advisory: Objenesis before 3.6 Type Confusion via Class Name Instantiator Cache third-party-advisory