CVE-2021-39144

HIGHNVD 8.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-03-10), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, nvd
Trending — 4 sources updated this weekExploited in the wild
8.5
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 98%CVSS: 8.5Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
8.5
EG Score
9.0(high)
EPSS
99.9%
KEV
⚠ Exploited

Published

August 23, 2021

Last Modified

October 24, 2025

Advisory Details (8)

Auto-updated Jun 2, 2026
Patch available. Sources: github.
generic

[SECURITY] [DSA 5004-1] libxstream-java security update

https://www.debian.org/security/2021/dsa-5004
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20210923-0003/
generic

[SECURITY] Fedora 34 Update: xstream-1.4.18-2.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/
generic

[SECURITY] Fedora 35 Update: xstream-1.4.18-2.fc35 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/
generic

[SECURITY] Fedora 33 Update: xstream-1.4.18-2.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/
generic Patch Available

[SECURITY] [DLA 2769-1] libxstream-java security update

https://lists.debian.org/debian-lts-announce/2021/09/msg00017.html
github Patch Available

XStream is vulnerable to a Remote Command Execution attack · Advisory · x-stream/xstream · GitHub

https://github.com/x-stream/xstream/security/advisories/GHSA-j9h8-phrw-h4fh
generic

Packet Storm

http://packetstormsecurity.com/files/169859/VMware-NSX-Manager-XStream-Unauthenticated-Remote-Code-Execution.html

Vendor Advisories for CVE-2021-39144(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibxstream-java (1.4.7-1ubuntu0.1+esm1) @ trusty2026-07-12ubuntu
redhatrh-sso7-keycloak2023-06-27redhat
redhatxstream2023-03-17redhat
redhatpatch2021-11-23redhat
redhatxstream-0:1.3.1-16.el7_92021-10-25redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
com.thoughtworks.xstream:xstream0.1 ... 1.4.9 (42 versions)1.4.18—

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(8)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 94× in last 7d / 403× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 563 total refreshes for this CVE.

  1. 2026-07-12 01:43 UTCEG score recompute
  2. 2026-07-12 01:43 UTCVendor advisory
  3. 2026-07-11 21:58 UTCEG score recompute
  4. 2026-07-11 21:58 UTCVendor advisory
  5. 2026-07-11 18:13 UTCEG score recompute
  6. 2026-07-11 18:13 UTCVendor advisory
  7. 2026-07-11 14:28 UTCEG score recompute
  8. 2026-07-11 14:28 UTCVendor advisory
  9. 2026-07-11 10:43 UTCEG score recompute
  10. 2026-07-11 10:43 UTCVendor advisory
  11. 2026-07-11 06:58 UTCEG score recompute
  12. 2026-07-11 06:58 UTCVendor advisory
  13. 2026-07-11 03:13 UTCEG score recompute
  14. 2026-07-11 03:13 UTCVendor advisory
  15. 2026-07-10 23:28 UTCEG score recompute
  16. 2026-07-10 23:28 UTCVendor advisory
  17. 2026-07-10 19:43 UTCEG score recompute
  18. 2026-07-10 19:43 UTCVendor advisory
  19. 2026-07-10 17:52 UTCCISA KEV update
  20. 2026-07-10 15:58 UTCEG score recompute
  21. 2026-07-10 15:58 UTCVendor advisory
  22. 2026-07-10 12:13 UTCEG score recompute
  23. 2026-07-10 12:13 UTCVendor advisory
  24. 2026-07-10 08:27 UTCEG score recompute
  25. 2026-07-10 08:27 UTCVendor advisory
Show 75 more
  1. 2026-07-10 04:43 UTCEG score recompute
  2. 2026-07-10 04:43 UTCVendor advisory
  3. 2026-07-10 00:57 UTCEG score recompute
  4. 2026-07-10 00:57 UTCVendor advisory
  5. 2026-07-09 21:12 UTCEG score recompute
  6. 2026-07-09 21:12 UTCVendor advisory
  7. 2026-07-09 19:07 UTCEPSS rescore
  8. 2026-07-09 17:28 UTCEG score recompute
  9. 2026-07-09 17:28 UTCVendor advisory
  10. 2026-07-09 13:42 UTCEG score recompute
  11. 2026-07-09 13:42 UTCVendor advisory
  12. 2026-07-09 09:57 UTCEG score recompute
  13. 2026-07-09 09:57 UTCVendor advisory
  14. 2026-07-09 06:13 UTCEG score recompute
  15. 2026-07-09 06:13 UTCVendor advisory
  16. 2026-07-09 02:28 UTCEG score recompute
  17. 2026-07-09 02:28 UTCVendor advisory
  18. 2026-07-08 22:44 UTCEG score recompute
  19. 2026-07-08 22:44 UTCVendor advisory
  20. 2026-07-08 18:59 UTCEG score recompute
  21. 2026-07-08 18:59 UTCVendor advisory
  22. 2026-07-08 15:12 UTCEG score recompute
  23. 2026-07-08 15:12 UTCVendor advisory
  24. 2026-07-08 11:26 UTCEG score recompute
  25. 2026-07-08 11:26 UTCVendor advisory
  26. 2026-07-08 07:41 UTCEG score recompute
  27. 2026-07-08 07:41 UTCVendor advisory
  28. 2026-07-08 03:57 UTCEG score recompute
  29. 2026-07-08 03:57 UTCVendor advisory
  30. 2026-07-08 00:11 UTCEG score recompute
  31. 2026-07-08 00:11 UTCVendor advisory
  32. 2026-07-07 20:25 UTCEG score recompute
  33. 2026-07-07 20:25 UTCVendor advisory
  34. 2026-07-07 19:01 UTCCISA KEV update
  35. 2026-07-07 17:16 UTCCISA KEV update
  36. 2026-07-07 16:40 UTCEG score recompute
  37. 2026-07-07 16:40 UTCVendor advisory
  38. 2026-07-07 12:56 UTCEG score recompute
  39. 2026-07-07 12:56 UTCVendor advisory
  40. 2026-07-07 09:10 UTCEG score recompute
  41. 2026-07-07 09:10 UTCVendor advisory
  42. 2026-07-07 05:25 UTCEG score recompute
  43. 2026-07-07 05:25 UTCVendor advisory
  44. 2026-07-07 01:39 UTCEG score recompute
  45. 2026-07-07 01:39 UTCVendor advisory
  46. 2026-07-06 21:54 UTCEG score recompute
  47. 2026-07-06 21:54 UTCVendor advisory
  48. 2026-07-06 18:09 UTCEG score recompute
  49. 2026-07-06 18:09 UTCVendor advisory
  50. 2026-07-06 14:24 UTCEG score recompute
  51. 2026-07-06 14:24 UTCVendor advisory
  52. 2026-07-06 10:39 UTCEG score recompute
  53. 2026-07-06 10:39 UTCVendor advisory
  54. 2026-07-06 06:53 UTCEG score recompute
  55. 2026-07-06 06:53 UTCVendor advisory
  56. 2026-07-06 03:08 UTCEG score recompute
  57. 2026-07-06 03:08 UTCVendor advisory
  58. 2026-07-05 23:22 UTCEG score recompute
  59. 2026-07-05 23:22 UTCVendor advisory
  60. 2026-07-05 19:37 UTCEG score recompute
  61. 2026-07-05 19:37 UTCVendor advisory
  62. 2026-07-05 15:52 UTCEG score recompute
  63. 2026-07-05 15:52 UTCVendor advisory
  64. 2026-07-05 12:07 UTCEG score recompute
  65. 2026-07-05 12:07 UTCVendor advisory
  66. 2026-07-05 08:22 UTCEG score recompute
  67. 2026-07-05 08:22 UTCVendor advisory
  68. 2026-07-05 04:37 UTCEG score recompute
  69. 2026-07-05 04:37 UTCVendor advisory
  70. 2026-07-05 00:49 UTCEG score recompute
  71. 2026-07-05 00:49 UTCVendor advisory
  72. 2026-07-04 21:04 UTCEG score recompute
  73. 2026-07-04 21:04 UTCVendor advisory
  74. 2026-07-04 17:19 UTCEG score recompute
  75. 2026-07-04 17:19 UTCVendor advisory

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitexploit/linux/http/vmware_nsxmgr_xstream_rce_cve_2021_39144✓ verified
    First seen Oct 25, 2022

    VMware NSX Manager XStream unauthenticated RCE

    Open source ↗
  • Nucleihttp/cves/2021/CVE-2021-39144.yaml
    First seen Jan 1, 2021

    XStream 1.4.18 - Remote Code Execution

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2021-39144?
CVE-2021-39144 is a high vulnerability published on August 23, 2021. 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…
When was CVE-2021-39144 disclosed?
CVE-2021-39144 was first published in the National Vulnerability Database on August 23, 2021, with the most recent update on October 24, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-39144 actively exploited?
Yes. CISA added CVE-2021-39144 to the Known Exploited Vulnerabilities catalog on March 10, 2023, affecting XStream XStream. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-39144?
CVE-2021-39144 has a CVSS v3 base score of 8.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-39144?
CVE-2021-39144 affects XStream XStream. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-39144?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-39144, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-39144

Explore →

Is Your Infrastructure Affected by CVE-2021-39144?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs