CVE-2021-36580

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2023-07-27. NVD baseline CVSS 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 2%CVSS: 6.1Exploit: NoneExposed: 0

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

Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via the referer parameter.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
72.1%
KEV
Not listed

Published

July 27, 2023

Last Modified

July 9, 2026

Advisory Details (1)

Auto-updated Jul 9, 2026
No patch confirmed yet.
generic

爱思华宝 WebClient

http://mail.ziyan.com

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 50× 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.

  1. 2026-07-23 14:16 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 02:02 UTCEG score recompute
  4. 2026-07-22 22:49 UTCEG score recompute
  5. 2026-07-22 14:06 UTCEPSS rescore
  6. 2026-07-22 14:06 UTCEPSS rescore
  7. 2026-07-21 15:22 UTCEPSS rescore
  8. 2026-07-21 15:22 UTCEPSS rescore
  9. 2026-07-20 17:05 UTCEPSS rescore
  10. 2026-07-19 14:29 UTCEPSS rescore
  11. 2026-07-19 14:29 UTCEPSS rescore
  12. 2026-07-19 02:27 UTCEPSS rescore
  13. 2026-07-18 10:02 UTCEPSS rescore
  14. 2026-07-18 10:02 UTCEPSS rescore
  15. 2026-07-16 17:00 UTCEPSS rescore
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  17. 2026-07-15 16:55 UTCEPSS rescore
  18. 2026-07-15 01:58 UTCEPSS rescore
  19. 2026-07-13 22:27 UTCEPSS rescore
  20. 2026-07-13 06:10 UTCEPSS rescore
  21. 2026-07-12 05:44 UTCEPSS rescore
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  23. 2026-07-11 08:25 UTCEPSS rescore
  24. 2026-07-11 08:25 UTCEPSS rescore
  25. 2026-07-09 19:07 UTCEPSS rescore
Show 71 more
  1. 2026-07-09 02:56 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  2. 2026-07-09 01:24 UTCMITRE cvelistV5
  3. 2026-07-08 15:12 UTCEPSS rescore
  4. 2026-07-07 13:43 UTCEPSS rescore
  5. 2026-07-06 16:25 UTCEPSS rescore
  6. 2026-07-06 02:21 UTCEPSS rescore
  7. 2026-07-05 17:59 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  8. 2026-07-05 16:09 UTCMITRE cvelistV5
  9. 2026-07-05 02:28 UTCEPSS rescore
  10. 2026-07-05 02:28 UTCEPSS rescore
  11. 2026-07-04 06:29 UTCEPSS rescore
  12. 2026-07-04 06:29 UTCEPSS rescore
  13. 2026-07-01 15:04 UTCEPSS rescore
  14. 2026-06-30 23:20 UTCEPSS rescore
  15. 2026-06-30 23:20 UTCEPSS rescore
  16. 2026-06-28 14:05 UTCEPSS rescore
  17. 2026-06-28 04:54 UTCEPSS rescore
  18. 2026-06-28 04:54 UTCEPSS rescore
  19. 2026-06-27 03:06 UTCEPSS rescore
  20. 2026-06-25 13:48 UTCEPSS rescore
  21. 2026-06-25 13:48 UTCEPSS rescore
  22. 2026-06-24 14:03 UTCEPSS rescore
  23. 2026-06-24 14:03 UTCEPSS rescore
  24. 2026-06-23 21:31 UTCEPSS rescore
  25. 2026-06-23 21:31 UTCEPSS rescore
  26. 2026-06-21 14:55 UTCEPSS rescore
  27. 2026-06-21 01:58 UTCEPSS rescore
  28. 2026-06-21 01:58 UTCEPSS rescore
  29. 2026-06-19 19:24 UTCEPSS rescore
  30. 2026-06-19 19:24 UTCEPSS rescore
  31. 2026-06-18 17:51 UTCEPSS rescore
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  34. 2026-06-16 17:51 UTCEPSS rescore
  35. 2026-06-16 17:51 UTCEPSS rescore
  36. 2026-06-15 17:46 UTCEPSS rescore
  37. 2026-06-14 23:15 UTCEPSS rescore
  38. 2026-06-13 22:58 UTCEPSS rescore
  39. 2026-06-13 22:58 UTCEPSS rescore
  40. 2026-06-12 23:10 UTCEPSS rescore
  41. 2026-06-12 23:10 UTCEPSS rescore
  42. 2026-06-11 13:58 UTCEPSS rescore
  43. 2026-06-10 22:16 UTCEPSS rescore
  44. 2026-06-10 13:20 UTCEPSS rescore
  45. 2026-06-08 14:15 UTCEPSS rescore
  46. 2026-06-08 14:15 UTCEPSS rescore
  47. 2026-06-07 15:23 UTCEPSS rescore
  48. 2026-06-07 15:23 UTCEPSS rescore
  49. 2026-06-06 13:46 UTCEPSS rescore
  50. 2026-06-06 13:46 UTCEPSS rescore
  51. 2026-06-06 13:46 UTCEPSS rescore
  52. 2026-06-05 22:45 UTCEPSS rescore
  53. 2026-06-05 06:09 UTCEPSS rescore
  54. 2026-06-05 06:09 UTCEPSS rescore
  55. 2026-06-04 13:10 UTCEPSS rescore
  56. 2026-06-04 13:10 UTCEPSS rescore
  57. 2026-06-02 20:11 UTCEPSS rescore
  58. 2026-06-02 20:11 UTCEPSS rescore
  59. 2026-05-31 22:29 UTCEPSS rescore
  60. 2026-05-31 22:29 UTCEPSS rescore
  61. 2026-05-31 00:15 UTCEPSS rescore
  62. 2026-05-31 00:15 UTCEPSS rescore
  63. 2026-05-29 13:42 UTCEPSS rescore
  64. 2026-05-29 13:42 UTCEPSS rescore
  65. 2026-05-28 13:43 UTCEPSS rescore
  66. 2026-05-28 13:43 UTCEPSS rescore
  67. 2026-05-27 13:39 UTCEPSS rescore
  68. 2026-05-27 13:39 UTCEPSS rescore
  69. 2026-05-27 13:39 UTCEPSS rescore
  70. 2026-05-24 20:32 UTCEG score recompute
  71. 2026-05-24 20:32 UTCGHSA enrichment

Publicly available exploits

(1 reference)

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

  • Nucleihttp/cves/2021/CVE-2021-36580.yaml
    First seen Jan 1, 2021

    IceWarp Mail Server - Open Redirect

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-36580?
CVE-2021-36580 is a medium vulnerability published on July 27, 2023. Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via the referer parameter.
When was CVE-2021-36580 disclosed?
CVE-2021-36580 was first published in the National Vulnerability Database on July 27, 2023, with the most recent update on July 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-36580 actively exploited?
CVE-2021-36580 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 72.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-36580?
CVE-2021-36580 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2021-36580?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-36580, 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

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