# CVE-2021-21349: libxstream-java: XStream is a Java library to serialize objects to XML and back again

CVE-2021-21349 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-2021-21349
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.4683
- 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 request data from internal resources that are notpublicly available only by manipulating the processed input stream. No useris affected, who followed the recommendation to setup XStream's securityframework with a whitelist limited to the minimal required types. If yourely on XStream's default blacklist of the Security Framework, you willhave to use at least version 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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