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Fencer Intel
medium 6.3

CVE-2020-26258 json

Server-Side Forgery Request can be activated unmarshalling with XStream

published 5y ago modified last mo. also GHSA-4cch-wxpw-8p28 , EUVD-2020-1481

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
81.8%
EPSS 81.8% chance of exploitation in 30 days, percentile 99.6%
public exploits
0
none known, plus a Nuclei check

Summary

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.

Patch / fix

  • maven com.thoughtworks.xstream:xstream 1.4.15
  • apache struts 6.0.0
  • xstream xstream 1.4.15
  • libxstream-java Debian 14, Debian 13, Debian 12 1.4.15-1

debian advisories DEBIAN-CVE-2020-26258

  • libxstream-java Ubuntu 18.04 LTS 1.4.11.1-1~18.04.1
  • libxstream-java Ubuntu 20.04 LTS 1.4.11.1-1ubuntu0.1
  • libxstream-java Ubuntu Pro 14.04 LTS 1.4.7-1ubuntu0.1+esm2
  • libxstream-java Ubuntu Pro 16.04 LTS 1.4.8-1ubuntu0.1+esm3

ubuntu advisories UBUNTU-CVE-2020-26258

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xpp3 Manager Server Module 4.1 1.1.4c-11.2.2
  • smdba Manager Server Module 4.1 1.7.8-0.3.6.2
  • rhnlib Manager Server Module 4.1, Manager Proxy Module 4.1 4.1.3-4.3.2
  • cobbler Manager Server Module 4.1 3.0.0+git20190806.32c4bae0-5.6.4
  • xstream Manager Server Module 4.1 1.4.15-3.5.2
  • mgr-osad Manager Server Module 4.1, Manager Proxy Module 4.1 4.1.5-2.9.4
  • mgr-libmod Manager Server Module 4.1 4.1.7-3.16.2
  • susemanager Manager Server Module 4.1 4.1.24-3.20.2

suse advisories SUSE-SU-2021:0906-1SUSE-SU-2021:0176-1

  • xstream openSUSE Tumbleweed 1.4.18-1.1
  • xstream openSUSE Leap 15.2 1.4.15-lp152.2.3.1

opensuse advisories openSUSE-SU-2024:10592-1openSUSE-SU-2021:0140-1

Is CVE-2020-26258 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-26258 updated cvss 7.7

XStream: Server-Side Forgery Request vulnerability can be activated when unmarshalling

  • Red Hat BPM Suite 6 xstream Red Hat Enterprise Linux 7 xstream, xstream-javadoc
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Integration Camel K 1 xstream Red Hat Integration Camel Quarkus 1 xstream
    affected: workaround, no fix available
  • Red Hat JBoss A-MQ 6 xstream Red Hat JBoss BRMS 6 xstream Red Hat JBoss Data Grid 7 xstream Red Hat JBoss Data Virtualization 6 xstream Red Hat JBoss Fuse 6 xstream Red Hat JBoss Fuse Service Works 6 xstream
    +1 more products
    Red Hat JBoss SOA Platform 5 xstream
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Data Grid 8.2.0
    fixed: vendor fix RHSA-2021:2139
  • Red Hat Fuse 7.9
    fixed: vendor fix RHSA-2021:3140
  • Red Hat Integration
    fixed: vendor fix RHSA-2021:3205
  • Red Hat Integration Camel Quarkus 2
    fixed: vendor fix RHSA-2021:4767
  • Red Hat RHDM 7.11.0
    fixed: vendor fix RHSA-2021:2476
show 2 more
  • Red Hat RHPAM 7.11.0
    fixed: vendor fix RHSA-2021:2475
  • Red Hat OpenShift Container Platform 3.11 jenkins Red Hat OpenShift Container Platform 4 jenkins
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last mo.

Exploit prediction

81.82% chance of exploitation in the next 30 days, higher than 99.6% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template XStream <1.4.15 - Server-Side Request Forgery nuclei detection template
  • x-stream.github.io https://x-stream.github.io/CVE-2020-26258.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub 3.1 6.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven com.thoughtworks.xstream:xstream
<1.4.15
1.4.15

Affected products

  • x-stream xstream

Classification

Weakness
  • CWE-918 Server-Side Request Forgery

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.