CVE-2020-9818

CRITICALNVD 8.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 2.3%CVSS: 8.8Exploit: cisa kev · ssvc activeExposed services: Not assessed

A fix is available — apply it.

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.

CVSS v3
8.8
EG Score
9.0CRITICALhigh confidence
EG Risk
81
EG Risk 81/100CISA SSVC

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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Attend at medium and Act at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
2.3%
EPSS %ILE
82nd
KEV
⚠ Exploited

CISA SSVCTrack at low, Attend at medium and Act at high mission impact.

A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.

Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

June 9, 2020

Last Modified

October 23, 2025

Advisory Details (4)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-9818
generic

About the security content of watchOS 6.2.5 - Apple Support

https://support.apple.com/HT211175
generic

About the security content of iOS 12.4.7 - Apple Support

https://support.apple.com/HT211169
generic

About the security content of iOS 13.5 and iPadOS 13.5 - Apple Support

https://support.apple.com/HT211168

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 55× in last 7d / 239× 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 1,011 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2020-9818?
CVE-2020-9818 is a critical vulnerability published on June 9, 2020. An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.
When was CVE-2020-9818 disclosed?
CVE-2020-9818 was first published on June 9, 2020, with the most recent update on October 23, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-9818 actively exploited?
Yes. CISA added CVE-2020-9818 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Apple iOS, iPadOS, and watchOS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2020-9818?
CVE-2020-9818 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2020-9818?
CVE-2020-9818 affects Apple iOS, iPadOS, and watchOS.
How do I remediate CVE-2020-9818?
A fix for CVE-2020-9818 is available: update to the fixed version the vendor names in its advisory.

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