CVE-2021-39144 | XStream is vulnerable to a Remote Command Execution attack

Exp

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.

Published: 2021-08-23 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-39144 is rated Critical Active Threat (93.6/100): CVSS High severity, with high exploitation likelihood (EPSS 98.12%, 100th percentile). CISA KEV confirms active exploitation (added 2023-03-10) affecting XStream / XStream. a weakness (CWE-306) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-39144

Name: XStream Remote Code Execution Vulnerability · CISA KEV detail

Exploit added: 2023-03-10

Action due: 2023-03-31

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2021-39144

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-39144

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-03 98.51% 98.12% -0.39%
2 2026-06-15 94.25% 98.51% +4.25%
3 2026-03-10 — 94.25% —

Full EPSS history (46 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-39144

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 6.0 [email protected]
8.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 6.0 [email protected]
6.0 2.0 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 6.8 6.4 [email protected]

Weakness enumeration for CVE-2021-39144

GitHub Security Advisory for CVE-2021-39144

GHSA-j9h8-phrw-h4fh · Severity: high · Ecosystem: maven — XStream is vulnerable to a Remote Command Execution attack

OS Trackers for CVE-2021-39144

vendor priority summary link
debian not yet assigned CVE-2021-39144 not yet assigned priority: Debian including 1 source packages (libxstream-java), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-39144
redhat high — https://access.redhat.com/security/cve/CVE-2021-39144
suse high CVE-2021-39144 severity important: SUSE including 247 source package names (5.0.0-beta1.2.122:xstream-1.4.18-3.14.1, 5.1.0.6.40:xstream-1.4.18-3.14.1, …), 282 product×package rows across 33 product lines (Container suse/manager/5.0/x86_64/server, Container suse/multi-linux-manager/5.1/x86_64/server, … (33 product lines)): Known Affected 231, Fixed 51. https://www.suse.com/security/cve/CVE-2021-39144/
ubuntu medium CVE-2021-39144 medium priority: Ubuntu including 1 source packages (libxstream-java), 10 status rows across 10 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, trusty, upstream, xenial): not-affected 5, ignored 2, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2021-39144

Affected software / configurations for CVE-2021-39144

Vendor Product Version Raw CPE
xstream xstream < 1.4.18 cpe:2.3:a:xstream:xstream:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
netapp snapmanager — cpe:2.3:a:netapp:snapmanager:-:*:*:*:*:oracle:*:*
netapp snapmanager — cpe:2.3:a:netapp:snapmanager:-:*:*:*:*:sap:*:*
oracle business_activity_monitoring 12.2.1.4.0 cpe:2.3:a:oracle:business_activity_monitoring:12.2.1.4.0:*:*:*:*:*:*:*
oracle commerce_guided_search 11.3.2 cpe:2.3:a:oracle:commerce_guided_search:11.3.2:*:*:*:*:*:*:*
oracle communications_billing_and_revenue_management_elastic_charging_engine 11.3 cpe:2.3:a:oracle:communications_billing_and_revenue_management_elastic_charging_engine:11.3:*:*:*:*:*:*:*
oracle communications_billing_and_revenue_management_elastic_charging_engine 12.0 cpe:2.3:a:oracle:communications_billing_and_revenue_management_elastic_charging_engine:12.0:*:*:*:*:*:*:*
oracle communications_cloud_native_core_automated_test_suite 1.9.0 cpe:2.3:a:oracle:communications_cloud_native_core_automated_test_suite:1.9.0:*:*:*:*:*:*:*
oracle communications_cloud_native_core_binding_support_function 1.10.0 cpe:2.3:a:oracle:communications_cloud_native_core_binding_support_function:1.10.0:*:*:*:*:*:*:*
oracle communications_cloud_native_core_policy 1.14.0 cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.14.0:*:*:*:*:*:*:*
oracle communications_unified_inventory_management 7.3.4 cpe:2.3:a:oracle:communications_unified_inventory_management:7.3.4:*:*:*:*:*:*:*
oracle communications_unified_inventory_management 7.3.5 cpe:2.3:a:oracle:communications_unified_inventory_management:7.3.5:*:*:*:*:*:*:*
oracle communications_unified_inventory_management 7.4.0 cpe:2.3:a:oracle:communications_unified_inventory_management:7.4.0:*:*:*:*:*:*:*
oracle communications_unified_inventory_management 7.4.1 cpe:2.3:a:oracle:communications_unified_inventory_management:7.4.1:*:*:*:*:*:*:*
oracle communications_unified_inventory_management 7.4.2 cpe:2.3:a:oracle:communications_unified_inventory_management:7.4.2:*:*:*:*:*:*:*
oracle retail_xstore_point_of_service 16.0.6 cpe:2.3:a:oracle:retail_xstore_point_of_service:16.0.6:*:*:*:*:*:*:*
oracle retail_xstore_point_of_service 17.0.4 cpe:2.3:a:oracle:retail_xstore_point_of_service:17.0.4:*:*:*:*:*:*:*
oracle retail_xstore_point_of_service 18.0.3 cpe:2.3:a:oracle:retail_xstore_point_of_service:18.0.3:*:*:*:*:*:*:*
oracle retail_xstore_point_of_service 19.0.2 cpe:2.3:a:oracle:retail_xstore_point_of_service:19.0.2:*:*:*:*:*:*:*
oracle retail_xstore_point_of_service 20.0.1 cpe:2.3:a:oracle:retail_xstore_point_of_service:20.0.1:*:*:*:*:*:*:*
oracle utilities_framework 4.2.0.2.0 cpe:2.3:a:oracle:utilities_framework:4.2.0.2.0:*:*:*:*:*:*:*
oracle utilities_framework 4.2.0.3.0 cpe:2.3:a:oracle:utilities_framework:4.2.0.3.0:*:*:*:*:*:*:*
oracle utilities_framework 4.3.0.1.0 cpe:2.3:a:oracle:utilities_framework:4.3.0.1.0:*:*:*:*:*:*:*
oracle utilities_framework 4.3.0.6.0 cpe:2.3:a:oracle:utilities_framework:4.3.0.6.0:*:*:*:*:*:*:*
oracle utilities_framework 4.4.0.0.0 cpe:2.3:a:oracle:utilities_framework:4.4.0.0.0:*:*:*:*:*:*:*
oracle utilities_framework 4.4.0.2.0 cpe:2.3:a:oracle:utilities_framework:4.4.0.2.0:*:*:*:*:*:*:*
oracle utilities_framework 4.4.0.3.0 cpe:2.3:a:oracle:utilities_framework:4.4.0.3.0:*:*:*:*:*:*:*
oracle utilities_testing_accelerator 6.0.0.1.1 cpe:2.3:a:oracle:utilities_testing_accelerator:6.0.0.1.1:*:*:*:*:*:*:*
oracle webcenter_portal 12.2.1.3.0 cpe:2.3:a:oracle:webcenter_portal:12.2.1.3.0:*:*:*:*:*:*:*
oracle webcenter_portal 12.2.1.4.0 cpe:2.3:a:oracle:webcenter_portal:12.2.1.4.0:*:*:*:*:*:*:*

References for CVE-2021-39144

URL Tags
http://packetstormsecurity.com/files/169859/VMware-NSX-Manager-XStream-Unauthenticated-Remote-Code-Execution.html Exploit Third Party Advisory VDB Entry
https://github.com/x-stream/xstream/security/advisories/GHSA-j9h8-phrw-h4fh Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00017.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/ Broken Link Mailing List Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/ Broken Link Mailing List Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/ Broken Link Mailing List Release Notes
https://security.netapp.com/advisory/ntap-20210923-0003/ Third Party Advisory
https://www.debian.org/security/2021/dsa-5004 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Patch Third Party Advisory
https://x-stream.github.io/CVE-2021-39144.html Exploit Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-39144 US Government Resource
cvelogic Threat Intelligence