# CVE-2021-21344: libxstream-java: XStream is a Java library to serialize objects to XML and back again

CVE-2021-21344 is fixed in libxstream-java on 1 platform, first by libxstream-java 1.4.11.1-1~18.04.2, released March 22, 2021. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-21344
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.7598
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 22, 2021

## Description

XStream is a Java library to serialize objects to XML and back again. InXStream before version 1.4.16, there is a vulnerability which may allow aremote attacker to load and execute arbitrary code from a remote host onlyby manipulating the processed input stream. No user is affected, whofollowed the recommendation to setup XStream's security framework with awhitelist limited to the minimal required types. If you rely on XStream'sdefault blacklist of the Security Framework, you will have to use at leastversion 1.4.16.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libxstream-java Ubuntu 18.04.6 LTS (bionic) | 1.4.11.1-1~18.04.2 | [libxstream-java 1.4.11.1-1~18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libxstream-java-1.4.11.1-1-18.04.2.md) | Mar 22, 2021 |
| Linux | libxstream-java Ubuntu 20.04 LTS (focal) | 1.4.11.1-1ubuntu0.2 | [libxstream-java 1.4.11.1-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxstream-java-1.4.11.1-1ubuntu0.2.md) | Mar 22, 2021 |
| Linux | libxstream-java Ubuntu 24.10 (oracular) | 1.4.15-2 | [libxstream-java 1.4.15-2](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-libxstream-java-1.4.15-2.md) | Jan 16, 2026 |

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