Description
XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability which may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| x-stream | xstream | < 1.4.16 | — |
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 | libxstream-java | 1.4.15-2 | — |
| Debian 13 | libxstream-java | 1.4.15-2 | — |
| Debian 12 | libxstream-java | 1.4.15-2 | — |
| Debian 9 | libxstream-java | 1.4.11.1-1+deb9u2 | DLA-2616-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libxstream-java | 1.4.11.1-1ubuntu0.2 | USN-4943-1 |
| Ubuntu 18.04 LTS | libxstream-java | 1.4.11.1-1~18.04.2 | USN-4943-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | libxstream-java | 1.4.8-1ubuntu0.1+esm3 | USN-6978-1 |
| Ubuntu Pro 14.04 LTS | libxstream-java | 1.4.7-1ubuntu0.1+esm2 | USN-6978-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | xstream | 1.4.16-3.8.1 | SUSE-SU-2021:1840-1 |
| SLES 15 SP2 | xstream | 1.4.16-3.8.1 | SUSE-SU-2021:1840-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Manager Server Module 4.2 | xstream | 1.4.16-3.8.1 | SUSE-SU-2021:1840-2 |
| SUSE Manager Server Module 4.1 | xstream | 1.4.16-3.8.1 | SUSE-SU-2021:1840-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xstream | 1.4.18-1.1 | openSUSE-SU-2024:10592-1 |
| openSUSE Leap 15.3 | xstream | 1.4.16-3.8.1 | openSUSE-SU-2021:1840-1 |
| openSUSE Leap 15.2 | xstream | 1.4.16-lp152.2.6.1 | openSUSE-SU-2021:0832-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | xstream +1 | 1.3.1-13.amzn2 | ALAS2-2021-1645 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
s-index/CVE-2021-21349 ★ 1 · May 9, 2021
XStream SSRF CVE-2021-21349
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | com.thoughtworks.xstream:xstream | < 1.4.16 | 1.4.16 | GHSA-f6hm-88x3-mfjv |
Advisories 10
- USN-6978-1 libxstream-java vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-4943-1 libxstream-java vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2616-1 libxstream-java - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10592-1 xstream-1.4.18-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1840-1 Security update for xstream SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1840-2 Security update for xstream SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1840-1 Security update for xstream SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2026-0180 Dell Data Protection Advisor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 20, 2026
- openSUSE-SU-2021:0832-1 Security update for xstream SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2021-1645 Important: xstream security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 3, 2024
References
- https://x-stream.github.io/security.html#workaround
- http://x-stream.github.io/changes.html#1.4.16
- https://github.com/x-stream/xstream/security/advisories/GHSA-f6hm-88x3-mfjv
- https://x-stream.github.io/CVE-2021-21349.html
- [debian-lts-announce] 20210403 [SECURITY] [DLA 2616-1] libxstream-java security update mailing-list
- [jmeter-dev] 20210406 [GitHub] [jmeter] sseide opened a new pull request #655: update x-stream to 1.4.16 (from 1.4.15) mailing-list
- [activemq-users] 20210427 Release date for ActiveMQ v5.16.2 to fix CVEs mailing-list
- https://security.netapp.com/advisory/ntap-20210430-0002/
- https://www.oracle.com//security-alerts/cpujul2021.html
- FEDORA-2021-fbad11014a vendor-advisory
- FEDORA-2021-d894ca87dc vendor-advisory
- https://www.oracle.com/security-alerts/cpuoct2021.html
- FEDORA-2021-5e376c0ed9 vendor-advisory
- DSA-5004 vendor-advisory
- https://www.oracle.com/security-alerts/cpujan2022.html