CVE-2021-21659

HIGHNVD 8.18.7▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.7 because EPSS predicts 67% probability of exploitation within the next 30 days (top 0.8% of all CVEs). NVD baseline CVSS 8.1 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
8.7EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 67%
CISA-KEV: Not listedEPSS PROB: 67%CVSS: 8.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Jenkins URLTrigger Plugin 0.48 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.

CVSS v3
8.1
EG Score
8.7(high)
EG Risk
70(Track)
EG Risk 70/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation67% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
67%
EPSS %ILE
99%
KEV
Not listed

Published

May 25, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

Jenkins Security Advisory 2021-05-25

https://www.jenkins.io/security/advisory/2021-05-25/#SECURITY-2341
generic

oss-security - Multiple vulnerabilities in Jenkins plugins

http://www.openwall.com/lists/oss-security/2021/05/25/3

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.jenkins-ci.plugins:urltrigger0.1 ... 0.9 (50 versions)0.49—

Data Freshness Timeline

(refreshed 7× in last 7d / 22× 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 116 total refreshes for this CVE.

  1. 2026-09-18 19:23 UTCEPSS rescore
  2. 2026-09-17 19:23 UTCEPSS rescore
  3. 2026-09-16 14:05 UTCEPSS rescore
  4. 2026-09-16 14:04 UTCEPSS rescore
  5. 2026-09-15 03:06 UTCEPSS rescore
  6. 2026-09-13 16:43 UTCEPSS rescore
  7. 2026-09-12 14:57 UTCEPSS rescore
  8. 2026-09-10 09:29 UTCEPSS rescore
  9. 2026-09-06 17:01 UTCOSV refresh
  10. 2026-09-06 13:44 UTCEPSS rescore
  11. 2026-09-06 13:44 UTCEPSS rescore
  12. 2026-09-05 15:25 UTCEPSS rescore
  13. 2026-09-04 13:57 UTCEPSS rescore
  14. 2026-09-04 05:03 UTCEPSS rescore
  15. 2026-09-02 14:08 UTCEPSS rescore
  16. 2026-09-01 13:50 UTCEPSS rescore
  17. 2026-08-30 19:14 UTCEPSS rescore
  18. 2026-08-30 01:19 UTCEPSS rescore
  19. 2026-08-28 21:37 UTCEPSS rescore
  20. 2026-08-26 14:42 UTCEPSS rescore
  21. 2026-08-21 23:46 UTCEPSS rescore
  22. 2026-08-20 22:52 UTCEPSS rescore
  23. 2026-08-20 02:45 UTCOSV refresh
  24. 2026-08-19 17:01 UTCEPSS rescore
  25. 2026-08-18 13:45 UTCEPSS rescore
Show 75 more
  1. 2026-08-17 13:43 UTCEPSS rescore
  2. 2026-08-16 02:11 UTCEPSS rescore
  3. 2026-08-15 01:27 UTCEPSS rescore
  4. 2026-08-13 21:57 UTCEPSS rescore
  5. 2026-08-12 13:47 UTCEPSS rescore
  6. 2026-08-11 13:38 UTCEPSS rescore
  7. 2026-08-07 16:23 UTCEPSS rescore
  8. 2026-08-05 19:14 UTCEPSS rescore
  9. 2026-08-04 21:57 UTCOSV refresh
  10. 2026-08-03 10:32 UTCEPSS rescore
  11. 2026-08-02 02:24 UTCEPSS rescore
  12. 2026-07-30 16:25 UTCEPSS rescore
  13. 2026-07-30 01:27 UTCEPSS rescore
  14. 2026-07-30 01:27 UTCEPSS rescore
  15. 2026-07-26 14:52 UTCEPSS rescore
  16. 2026-07-25 14:15 UTCEPSS rescore
  17. 2026-07-24 14:15 UTCEPSS rescore
  18. 2026-07-23 01:57 UTCEG score recompute▲ 0.60
  19. 2026-07-22 22:43 UTCEG score recompute
  20. 2026-07-22 14:05 UTCEPSS rescore
  21. 2026-07-20 17:04 UTCEPSS rescore
  22. 2026-07-19 02:26 UTCEPSS rescore
  23. 2026-07-18 19:59 UTCOSV refresh
  24. 2026-07-16 17:00 UTCEPSS rescore
  25. 2026-07-15 16:55 UTCEPSS rescore
  26. 2026-07-15 16:55 UTCEPSS rescore
  27. 2026-07-15 01:57 UTCEPSS rescore
  28. 2026-07-13 06:10 UTCEPSS rescore
  29. 2026-07-13 06:10 UTCEPSS rescore
  30. 2026-07-11 08:25 UTCEPSS rescore
  31. 2026-07-09 19:07 UTCEPSS rescore
  32. 2026-07-07 13:43 UTCEPSS rescore
  33. 2026-07-05 02:28 UTCEPSS rescore
  34. 2026-07-05 02:28 UTCEPSS rescore
  35. 2026-07-01 15:03 UTCEPSS rescore
  36. 2026-07-01 02:48 UTCOSV refresh
  37. 2026-06-30 23:20 UTCEPSS rescore
  38. 2026-06-30 23:20 UTCEPSS rescore
  39. 2026-06-29 14:04 UTCEPSS rescore
  40. 2026-06-29 14:04 UTCEPSS rescore
  41. 2026-06-27 03:06 UTCEPSS rescore
  42. 2026-06-27 03:06 UTCEPSS rescore
  43. 2026-06-25 13:48 UTCEPSS rescore
  44. 2026-06-25 13:48 UTCEPSS rescore
  45. 2026-06-24 14:03 UTCEPSS rescore
  46. 2026-06-24 14:03 UTCEPSS rescore
  47. 2026-06-23 21:31 UTCEPSS rescore
  48. 2026-06-23 21:31 UTCEPSS rescore
  49. 2026-06-17 17:51 UTCEPSS rescore
  50. 2026-06-16 17:50 UTCEPSS rescore
  51. 2026-06-15 17:46 UTCEPSS rescore
  52. 2026-06-14 23:15 UTCEPSS rescore
  53. 2026-06-13 22:58 UTCEPSS rescore
  54. 2026-06-13 05:13 UTCOSV refresh
  55. 2026-06-12 23:10 UTCEPSS rescore
  56. 2026-06-12 23:10 UTCEPSS rescore
  57. 2026-06-11 13:58 UTCEPSS rescore
  58. 2026-06-10 22:16 UTCEPSS rescore
  59. 2026-06-10 22:16 UTCEPSS rescore
  60. 2026-06-10 13:20 UTCEPSS rescore
  61. 2026-06-08 14:15 UTCEPSS rescore
  62. 2026-06-08 14:15 UTCEPSS rescore
  63. 2026-06-07 15:23 UTCEPSS rescore
  64. 2026-06-07 15:23 UTCEPSS rescore
  65. 2026-06-06 13:46 UTCEPSS rescore
  66. 2026-06-06 13:46 UTCEPSS rescore
  67. 2026-06-06 13:46 UTCEPSS rescore
  68. 2026-06-05 22:45 UTCEPSS rescore
  69. 2026-06-05 22:45 UTCEPSS rescore
  70. 2026-06-05 06:09 UTCEPSS rescore
  71. 2026-06-05 06:09 UTCEPSS rescore
  72. 2026-06-05 06:08 UTCEPSS rescore
  73. 2026-06-04 13:10 UTCEPSS rescore
  74. 2026-06-02 20:11 UTCEPSS rescore
  75. 2026-06-02 20:11 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-21659?
CVE-2021-21659 is a high vulnerability published on May 25, 2021. Jenkins URLTrigger Plugin 0.48 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.
When was CVE-2021-21659 disclosed?
CVE-2021-21659 was first published in the National Vulnerability Database on May 25, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-21659 actively exploited?
CVE-2021-21659 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 67% probability of exploitation in the next 30 days, which ranks it in the top 0.7% of all scored CVEs.
What is the CVSS score of CVE-2021-21659?
CVE-2021-21659 has a CVSS v3 base score of 8.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.7.
How do I remediate CVE-2021-21659?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21659, 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.

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