Description
XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| x-stream | xstream | < 1.4.15 | — |
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 | 1.4.15-1 | — |
| Debian 13 | libxstream-java | 1.4.15-1 | — |
| Debian 12 | libxstream-java | 1.4.15-1 | — |
| Debian 10 | libxstream-java | 1.4.11.1-1+deb10u2 | DSA-4828-1 |
| Debian 9 | libxstream-java | 1.4.11.1-1+deb9u1 | DLA-2507-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libxstream-java | 1.4.11.1-1ubuntu0.1 | USN-4943-1, USN-4714-1 |
| Ubuntu 18.04 LTS | libxstream-java | 1.4.11.1-1~18.04.1 | USN-4943-1, USN-4714-1 |
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 SP2 | xstream | 1.4.15-3.3.2 | SUSE-SU-2021:0176-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Manager Server Module 4.1 | cobbler | 3.0.0+git20190806.32c4bae0-5.6.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | grafana-formula | 0.4.0-3.6.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | mgr-libmod | 4.1.7-3.16.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | mgr-osad | 4.1.5-2.9.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | prometheus-exporters-formula | 0.9.0-3.19.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | prometheus-formula | 0.3.1-3.6.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | py26-compat-salt | 2016.11.10-6.11.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | rhnlib | 4.1.3-4.3.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | smdba | 1.7.8-0.3.6.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-backend | 4.1.21-4.22.7 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-client-tools | 4.1.9-4.12.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-config | 4.1.5-3.3.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-java | 4.1.30-3.31.7 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-utils | 4.1.14-3.12.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | spacewalk-web | 4.1.23-3.18.6 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | subscription-matcher | 0.26-3.6.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | susemanager | 4.1.24-3.20.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | susemanager-doc-indexes | 4.1-11.28.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | susemanager-docs_en | 4.1-11.28.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | susemanager-schema | 4.1.19-3.24.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | susemanager-sls | 4.1.21-3.26.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | xpp3 | 1.1.4c-11.2.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Server Module 4.1 | xstream | 1.4.15-3.5.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | mgr-osad | 4.1.5-2.9.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | rhnlib | 4.1.3-4.3.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | spacewalk-backend | 4.1.21-4.22.7 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | spacewalk-client-tools | 4.1.9-4.12.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | spacewalk-proxy | 4.1.4-3.9.4 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | spacewalk-proxy-installer | 4.1.6-3.3.2 | SUSE-SU-2021:0906-1 |
| SUSE Manager Proxy Module 4.1 | spacewalk-web | 4.1.23-3.18.6 | SUSE-SU-2021:0906-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xstream | 1.4.18-1.1 | openSUSE-SU-2024:10592-1 |
| openSUSE Leap 15.2 | xstream | 1.4.15-lp152.2.3.1 | openSUSE-SU-2021:0140-1 |
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 2 repositories
-
cuijiung/xstream-CVE-2020-26258 ★ 0 · Jul 11, 2025
-
Al1ex/CVE-2020-26258 ★ 0 · Jan 22, 2021
CVE-2020-26258 && XStream SSRF
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Automated scanner template
A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.
- XStream <1.4.15 - Server-Side Request Forgery http/cves/2020/CVE-2020-26258.yaml
Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | com.thoughtworks.xstream:xstream | < 1.4.15 | 1.4.15 | GHSA-4cch-wxpw-8p28 |
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
- DSA-4828-1 libxstream-java - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2507-1 libxstream-java - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4714-1 libxstream-java vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:10592-1 xstream-1.4.18-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0140-1 Security update for xstream SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0176-1 Security update for xstream SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0906-1 Security update for SUSE Manager Server 4.1 SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2026-0180 Dell Data Protection Advisor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 20, 2026
References
- https://github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28
- https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34@%3Ccommits.struts.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/12/msg00042.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB
- https://security.netapp.com/advisory/ntap-20210409-0005
- https://www.debian.org/security/2021/dsa-4828
- https://x-stream.github.io/CVE-2020-26258.html