CVE-2021-39147

XStream is vulnerable to an Arbitrary Code Execution attack

HIGH
8.5
CVSS Score
Published: August 23, 2021 at 06:05 PM UTC
Updated: October 7, 2026 at 09:17 PM UTC
15 products affected across 5 vendorsDebian LinuxFedoraSnapmanager

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Severity
HIGH8.5
Exploit prediction
EPSS 5%
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 load and execute arbitrary code from a remote host 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 exploitAutomatableTotal impact

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

CVSS

8.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-434CWE-502

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