GHSA-j563-grx4-pjpv
HIGHXStream can cause Denial of Service via stack overflow
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
com.thoughtworks.xstream:xstreamReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The vulnerability may allow a remote attacker to terminate the application with a stack overflow error resulting in a denial of service only by manipulating the processed input stream.
Patches
XStream 1.4.20 handles the stack overflow and raises an InputManipulationException instead.
Workarounds
The attack uses the hash code implementation for collections and maps to force recursive hash calculation causing a stack overflow. Following types of the Java runtime are affected:
- java.util.HashMap
- java.util.HashSet
- java.util.Hashtable
- java.util.LinkedHashMap
- java.util.LinkedHashSet
- Other third party collection implementations that use their element's hash code may also be affected
A simple solution is to catch the StackOverflowError in the client code calling XStream.
If your object graph does not use referenced elements at all, you may simply set the NO_REFERENCE mode:
XStream xstream = new XStream();
xstream.setMode(XStream.NO_REFERENCES);
If your object graph contains neither a Hashtable, HashMap nor a HashSet (or one of the linked variants of it) then you can use the security framework to deny the usage of these types:
XStream xstream = new XStream();
xstream.denyTypes(new Class[]{
java.util.HashMap.class, java.util.HashSet.class, java.util.Hashtable.class, java.util.LinkedHashMap.class, java.util.LinkedHashSet.class
});
Unfortunately these types are very common. If you only use HashMap or HashSet and your XML refers these only as default map or set, you may additionally change the default implementation of java.util.Map and java.util.Set at unmarshalling time::
xstream.addDefaultImplementation(java.util.TreeMap.class, java.util.Map.class);
xstream.addDefaultImplementation(java.util.TreeSet.class, java.util.Set.class);
However, this implies that your application does not care about the implementation of the map and all elements are comparable.
References
See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for CVE-2022-41966.
For more information
If you have any questions or comments about this advisory:
- Open an issue in XStream
- Contact us at XStream Google Group
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.thoughtworks.xstream:xstream | all versions | 1.4.20 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.thoughtworks.xstream:xstream. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update com.thoughtworks.xstream:xstream to 1.4.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j563-grx4-pjpv is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-j563-grx4-pjpv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-j563-grx4-pjpv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-j563-grx4-pjpv in your dependencies?
O3 detects GHSA-j563-grx4-pjpv across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.