Vulnerability Intelligence Report
XStream is vulnerable to a Remote Command Execution attack
CVE-2021-39144
XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker has sufficient rights to execute commands of the 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.
CISA KEV
Nuclei Template
SSVC: Active Exploitation
CVSS Base Score
8.5
HIGH
Exploitability:1.8
Impact Score:6.1
EPSS Probability:98.51%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-94 ↗CWE-94: Improper Control of Generation of Code ('Code Injection')
CWE-502 ↗CWE-502: Deserialization of Untrusted Data
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| x-stream | xstream | < 1.4.18 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
CISA KEV
ACTIVE IN CATALOG
Nuclei Template
SCANNER AVAILABLE
EPSS Score
98.510%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GitHub, Inc. · Vendor · USA |
| Reserved | 2021-08-16T00:00:00 |
| Published | 2021-08-23T00:00:00 |
| Last Updated | 2025-10-21T23:25:37 |
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