CVE-2021-39220

LOWNVD 3.53.5—
EchelonGraph scoreMEDIUM confidence

This low-severity CVE scores 3.5 under NVD CVSS v3. EPSS exploit probability: 0.8%, top 49% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
3.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 3.5Exploit: None knownExposed: 0

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

Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.

CVSS v3
3.5
EG Score
3.5(medium)
EG Risk
21(Track)
EG Risk 21/100SSVC: 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
Severity35% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
54%
KEV
Not listed

Published

October 25, 2021

Last Modified

November 21, 2024

References (6)

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 32× 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 153 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2021-39220?
CVE-2021-39220 is a low vulnerability published on October 25, 2021. Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended…
When was CVE-2021-39220 disclosed?
CVE-2021-39220 was first published in the National Vulnerability Database on October 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-2021-39220 actively exploited?
CVE-2021-39220 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 46.3% of all scored CVEs.
What is the CVSS score of CVE-2021-39220?
CVE-2021-39220 has a CVSS v3 base score of 3.5 (NVD).
How do I remediate CVE-2021-39220?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-39220, 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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