Vulnerabilities
Misconfiguration
Compliance
CVE Vulnerabilities

CVE-2021-39140

Deserialization of Untrusted Data

Published: Aug 23, 2021 | Modified: May 23, 2025
CVSS 3.x
6.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H
CVSS 2.x
6.3 MEDIUM
AV:N/AC:M/Au:S/C:N/I:N/A:C
RedHat/V2
RedHat/V3
6.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM
Vulnerability-free packages from our partners
root.io logo minimus.io logo echo.ai logo
Additional information
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2021-39140
CWEhttps://cwe.mitre.org/data/definitions/502.html

XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStreams security framework with a whitelist limited to the minimal required types. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

NameVendorStart VersionEnd Version
XstreamXstream*1.4.18 (excluding)
Red Hat Data Grid 8.3.0RedHatxstream*
Red Hat Enterprise Linux 7RedHatxstream-0:1.3.1-16.el7_9*
Red Hat IntegrationRedHatxstream*
Red Hat Integration Camel Quarkus 2RedHat*
RHDM 7.12.0RedHatxstream*
RHPAM 7.12.0RedHatxstream*
Libxstream-javaUbuntubionic*
Libxstream-javaUbuntuesm-apps/bionic*
Libxstream-javaUbuntuesm-apps/focal*
Libxstream-javaUbuntufocal*
Libxstream-javaUbuntuhirsute*
Libxstream-javaUbuntuimpish*
Libxstream-javaUbuntutrusty*
Libxstream-javaUbuntuxenial*

Potential Mitigations

  • Make fields transient to protect them from deserialization.
  • An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

References

Aqua Security is the largest pure-play cloud native security company, providing customers the freedom to innovate and run their businesses with minimal friction. The Aqua Cloud Native Security Platform provides prevention, detection, and response automation across the entire application lifecycle to secure the build, secure cloud infrastructure and secure running workloads wherever they are deployed.
Copyright © 2026 Aqua Security Software Ltd.   Privacy Policy | Terms of Use