CVE-2026-53421

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-20. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0

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

Improper Isolation or Compartmentalization vulnerability in Apache Syncope.

An administrator with adequate entitlements can achieve remote code execution through the connector subsystem by relying on scripted connectors' (REST and SQL) capability to run Groovy scripts.

This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.6, from 4.1.0-M0 through 4.1.1.

Users are recommended to upgrade to version 4.0.7 / 4.1.2, which fix this issue by hardening the Groovy security sandbox.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
59(Track*)
EG Risk 59/100SSVC: 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. It is distinct from the 0–10 EG Score, which measures severity.

How it’s computed
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
41.8%
KEV
Not listed

Published

July 20, 2026

Last Modified

July 21, 2026

Advisory Details (1)

Auto-updated Jul 21, 2026
No patch confirmed yet.
generic
https://lists.apache.org/thread/nmzvz6gb2ldm30wvyk613r8dfrb6r8yx

Vendor Advisories for CVE-2026-53421(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 116× in last 7d / 116× 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. 2026-07-22 23:39 UTCEG score recompute
  2. 2026-07-22 23:39 UTCGHSA enrichment
  3. 2026-07-22 14:08 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-21 15:24 UTCEG score recompute▲ 9.80
  6. 2026-07-21 15:24 UTCGHSA enrichment
  7. 2026-07-21 15:23 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  8. 2026-07-20 20:41 UTCNVD update
  9. 2026-07-20 19:12 UTCMITRE cvelistV5
  10. 2026-07-20 18:36 UTCGHSA enrichment
  11. 2026-07-20 18:34 UTCGHSA enrichment
  12. 2026-07-20 18:33 UTCGHSA enrichment
  13. 2026-07-20 18:33 UTCGHSA enrichment
  14. 2026-07-20 18:30 UTCGHSA enrichment
  15. 2026-07-20 18:29 UTCGHSA enrichment
  16. 2026-07-20 18:28 UTCGHSA enrichment
  17. 2026-07-20 18:27 UTCGHSA enrichment
  18. 2026-07-20 18:26 UTCGHSA enrichment
  19. 2026-07-20 18:26 UTCGHSA enrichment
  20. 2026-07-20 18:25 UTCGHSA enrichment
  21. 2026-07-20 18:25 UTCGHSA enrichment
  22. 2026-07-20 18:21 UTCGHSA enrichment
  23. 2026-07-20 18:18 UTCGHSA enrichment
  24. 2026-07-20 18:01 UTCGHSA enrichment
  25. 2026-07-20 17:59 UTCGHSA enrichment
Show 75 more
  1. 2026-07-20 17:58 UTCGHSA enrichment
  2. 2026-07-20 17:57 UTCGHSA enrichment
  3. 2026-07-20 17:56 UTCGHSA enrichment
  4. 2026-07-20 17:54 UTCGHSA enrichment
  5. 2026-07-20 17:53 UTCGHSA enrichment
  6. 2026-07-20 17:53 UTCGHSA enrichment
  7. 2026-07-20 17:52 UTCGHSA enrichment
  8. 2026-07-20 17:52 UTCGHSA enrichment
  9. 2026-07-20 17:51 UTCGHSA enrichment
  10. 2026-07-20 17:50 UTCGHSA enrichment
  11. 2026-07-20 17:50 UTCGHSA enrichment
  12. 2026-07-20 17:49 UTCGHSA enrichment
  13. 2026-07-20 17:49 UTCGHSA enrichment
  14. 2026-07-20 17:48 UTCGHSA enrichment
  15. 2026-07-20 17:48 UTCGHSA enrichment
  16. 2026-07-20 17:47 UTCGHSA enrichment
  17. 2026-07-20 17:47 UTCGHSA enrichment
  18. 2026-07-20 17:46 UTCGHSA enrichment
  19. 2026-07-20 17:46 UTCGHSA enrichment
  20. 2026-07-20 17:45 UTCGHSA enrichment
  21. 2026-07-20 17:45 UTCGHSA enrichment
  22. 2026-07-20 17:43 UTCGHSA enrichment
  23. 2026-07-20 17:43 UTCGHSA enrichment
  24. 2026-07-20 17:42 UTCGHSA enrichment
  25. 2026-07-20 17:42 UTCGHSA enrichment
  26. 2026-07-20 17:41 UTCGHSA enrichment
  27. 2026-07-20 17:40 UTCGHSA enrichment
  28. 2026-07-20 17:39 UTCGHSA enrichment
  29. 2026-07-20 17:38 UTCGHSA enrichment
  30. 2026-07-20 17:38 UTCGHSA enrichment
  31. 2026-07-20 17:37 UTCGHSA enrichment
  32. 2026-07-20 17:37 UTCGHSA enrichment
  33. 2026-07-20 17:36 UTCGHSA enrichment
  34. 2026-07-20 17:36 UTCGHSA enrichment
  35. 2026-07-20 17:35 UTCGHSA enrichment
  36. 2026-07-20 17:35 UTCGHSA enrichment
  37. 2026-07-20 17:34 UTCGHSA enrichment
  38. 2026-07-20 17:34 UTCGHSA enrichment
  39. 2026-07-20 17:33 UTCGHSA enrichment
  40. 2026-07-20 17:32 UTCGHSA enrichment
  41. 2026-07-20 17:31 UTCGHSA enrichment
  42. 2026-07-20 17:30 UTCGHSA enrichment
  43. 2026-07-20 17:29 UTCGHSA enrichment
  44. 2026-07-20 17:29 UTCGHSA enrichment
  45. 2026-07-20 17:28 UTCGHSA enrichment
  46. 2026-07-20 17:28 UTCGHSA enrichment
  47. 2026-07-20 17:27 UTCGHSA enrichment
  48. 2026-07-20 17:27 UTCGHSA enrichment
  49. 2026-07-20 17:26 UTCGHSA enrichment
  50. 2026-07-20 17:26 UTCGHSA enrichment
  51. 2026-07-20 17:25 UTCGHSA enrichment
  52. 2026-07-20 17:25 UTCGHSA enrichment
  53. 2026-07-20 17:24 UTCGHSA enrichment
  54. 2026-07-20 17:22 UTCGHSA enrichment
  55. 2026-07-20 17:22 UTCGHSA enrichment
  56. 2026-07-20 17:20 UTCGHSA enrichment
  57. 2026-07-20 17:19 UTCGHSA enrichment
  58. 2026-07-20 17:18 UTCGHSA enrichment
  59. 2026-07-20 17:18 UTCGHSA enrichment
  60. 2026-07-20 17:17 UTCGHSA enrichment
  61. 2026-07-20 17:15 UTCGHSA enrichment
  62. 2026-07-20 17:15 UTCGHSA enrichment
  63. 2026-07-20 17:09 UTCGHSA enrichment
  64. 2026-07-20 17:08 UTCGHSA enrichment
  65. 2026-07-20 17:08 UTCGHSA enrichment
  66. 2026-07-20 17:05 UTCGHSA enrichment
  67. 2026-07-20 17:04 UTCGHSA enrichment
  68. 2026-07-20 17:00 UTCGHSA enrichment
  69. 2026-07-20 16:59 UTCGHSA enrichment
  70. 2026-07-20 16:57 UTCGHSA enrichment
  71. 2026-07-20 16:56 UTCGHSA enrichment
  72. 2026-07-20 16:55 UTCGHSA enrichment
  73. 2026-07-20 16:54 UTCGHSA enrichment
  74. 2026-07-20 16:53 UTCGHSA enrichment
  75. 2026-07-20 16:52 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-53421?
CVE-2026-53421 is a critical vulnerability published on July 20, 2026. Improper Isolation or Compartmentalization vulnerability in Apache Syncope. An administrator with adequate entitlements can achieve remote code execution through the connector subsystem by relying on scripted connectors' (REST and SQL) capability to run Groovy scripts. This issue affects Apache…
When was CVE-2026-53421 disclosed?
CVE-2026-53421 was first published in the National Vulnerability Database on July 20, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53421 actively exploited?
CVE-2026-53421 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-53421?
CVE-2026-53421 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-53421?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53421, 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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