CVE-2021-39140

XStream can cause a Denial of Service

MEDIUM
6.3
CVSS Score
Published: August 23, 2021 at 06:15 PM UTC
Updated: October 7, 2026 at 09:17 PM UTC
15 products affected across 5 vendorsDebian LinuxFedoraSnapmanager

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Severity
MEDIUM6.3
Exploit prediction
EPSS 6%
SSVC
No known exploit

Description

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 XStream's 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.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-502CWE-835

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