CVE-2021-39140

MEDIUM6.5EPSS 0.14%

XStream can cause a Denial of Service

Published: 8/25/2021Modified: 3/13/2026
Also known as:GHSA-6wf9-jmg9-vxcc

Description

### Impact The 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 XStream's security framework with a whitelist limited to the minimal required types. ### Patches XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose. ### Workarounds See [workarounds](https://x-stream.github.io/security.html#workaround) for the different versions covering all CVEs. ### References See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for [CVE-2021-39140](https://x-stream.github.io/CVE-2021-39140.html). ### Credits The vulnerability was discovered and reported by Lai Han of nsfocus security team. ### For more information If you have any questions or comments about this advisory: * Open an issue in [XStream](https://github.com/x-stream/xstream/issues) * Contact us at [XStream Google Group](https://groups.google.com/group/xstream-user)

Affected packages (2)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1MEDIUM6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References (14)