CVE-2021-39144: XStream Remote Code Execution Vulnerability

Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-7ae3ca629904, updated 2026-11-02T23:39:54.475Z.

CISA Known Exploited Vulnerabilities

Name
XStream Remote Code Execution Vulnerability
Vendor
XStream
Product
XStream
Added to the catalog
2023-03-10
Due date for US federal agencies
2023-03-31
Weaknesses
CWE-94, CWE-502
Catalog version
2026.10.30

XStream contains a remote code execution vulnerability that allows an attacker to manipulate the processed input stream and replace or inject objects that result in the execution of a local command on the server. This vulnerability can affect multiple products, including but not limited to VMware Cloud Foundation.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status
Analyzed
Published
2021-08-23T18:15:12.087
Last modified
2026-06-17T04:03:09.313
Weaknesses
CWE-94, CWE-502, CWE-306

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.

MetricScoreSeverityVectorScored by
CVSS 3.18.5HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H[email protected] (Secondary)
CVSS 3.18.5HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H[email protected] (Primary)
CVSS 2.06MEDIUMAV:N/AC:M/Au:S/C:P/I:P/A:P[email protected] (Primary)

References

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:59.479Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-39144

CVE record

Title (CNA)
XStream is vulnerable to a Remote Command Execution attack
Assigner
GitHub_M
State
PUBLISHED
Published
2021-08-23T00:00:00.000Z
Updated
2025-10-21T23:25:37.489Z
Problem types
CWE-94: Improper Control of Generation of Code ('Code Injection'); CWE-502: Deserialization of Untrusted Data

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.

References

Read on 2026-11-03T01:08:46.663Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/39xxx/CVE-2021-39144.json

Also known as / affected packages

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

CWE-94: Improper Control of Generation of Code ('Code Injection')

D3FEND ontology version 1.6.0.

Read on 2026-11-02T23:54:29.667Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-94.json

CWE-306: Missing Authentication for Critical Function

D3FEND ontology version 1.6.0.

Read on 2026-11-02T23:55:55.098Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-306.json

CWE-502: Deserialization of Untrusted Data

D3FEND ontology version 1.6.0.

Read on 2026-11-02T23:56:57.230Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-502.json

MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/

Sources and licences

  • CISA

    Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.

    CC0 1.0 Universal

  • National Vulnerability Database (NIST)

    This product uses the NVD API but is not endorsed or certified by the NVD.

    NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)

  • CVE Program, The MITRE Corporation

    Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

    CVE Program Terms of Use ("CVE Usage" licence)

  • GitHub Advisory Database via OSV.dev

    GHSA-j9h8-phrw-h4fh: GitHub Advisory Database, https://github.com/advisories/GHSA-j9h8-phrw-h4fh. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/), provided as is, without warranties. Retrieved via OSV.dev (https://osv.dev/vulnerability/GHSA-j9h8-phrw-h4fh), which enriches records; fields selected and reformatted by ransomware-tracker.com.

    CC BY 4.0

  • MITRE D3FEND

    MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
    "The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/

    MITRE D3FEND Terms of Use (site + knowledge graph); source repo MIT

Cite this page

Dragons Eye Ransomware Tracker, "CVE-2021-39144: XStream Remote Code Execution Vulnerability",
entity page, dataset version ref-7ae3ca629904, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2021-39144 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-06-17T04:03:09.313.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2025-10-21T23:25:37.489Z.
Underlying source: GitHub Advisory Database, GHSA-j9h8-phrw-h4fh, via OSV.dev, modified 2026-07-08T06:27:23.933247432Z.
Underlying source: MITRE D3FEND, ontology version 1.6.0.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.

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