CVE-2021-30858

HIGHNVD 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, nvd
Trending — 4 sources updated this weekExploited in the wild
8.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 13%CVSS: 8.8Exploit: NoneExposed: 0

A fix is available — apply it.

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

CVSS v3
8.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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%
Action: Remediate soon — notable exploitation risk.
EPSS
96.0%
KEV
⚠ Exploited

Published

August 24, 2021

Last Modified

October 27, 2025

Advisory Details (10)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

oss-security - Re: WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006

http://www.openwall.com/lists/oss-security/2021/10/27/2
generic

oss-security - Re: WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006

http://www.openwall.com/lists/oss-security/2021/10/27/1
generic🔴 Active Exploitation

oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006

http://www.openwall.com/lists/oss-security/2021/10/26/9
generic🔴 Active Exploitation

oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2021-0005

http://www.openwall.com/lists/oss-security/2021/09/20/1
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-23-1 iOS 12.5.5

http://seclists.org/fulldisclosure/2021/Sep/50
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-20-7 Additional information for APPLE-SA-2021-09-13-3 macOS Big Sur 11.6

http://seclists.org/fulldisclosure/2021/Sep/39
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-20-6 Additional information for APPLE-SA-2021-09-13-1 iOS 14.8 and iPadOS 14.8

http://seclists.org/fulldisclosure/2021/Sep/38
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-13-5 Safari 14.1.2

http://seclists.org/fulldisclosure/2021/Sep/29
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-13-3 macOS Big Sur 11.6

http://seclists.org/fulldisclosure/2021/Sep/27
generic🔴 Active Exploitation

Full Disclosure: APPLE-SA-2021-09-13-1 iOS 14.8 and iPadOS 14.8

http://seclists.org/fulldisclosure/2021/Sep/25

Vendor Advisories for CVE-2021-30858(1)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibwebkit2gtk-4.0-dev (2.32.4-0ubuntu0.21.04.1) @ hirsute2026-07-22ubuntu
redhatwebkitgtk4-0:2.28.2-3.el72022-01-11redhat
redhatwebkit2gtk3-0:2.24.4-4.el8_22022-01-11redhat
redhatwebkit2gtk3-0:2.24.4-4.el8_12021-11-16redhat
redhatwebkit2gtk3-0:2.30.4-3.el8_42021-11-02redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

Additional Vendor Advisories

(4)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 45× in last 7d / 233× 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 460 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2021-30858?
CVE-2021-30858 is a high vulnerability published on August 24, 2021. A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
When was CVE-2021-30858 disclosed?
CVE-2021-30858 was first published in the National Vulnerability Database on August 24, 2021, with the most recent update on October 27, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-30858 actively exploited?
Yes. CISA added CVE-2021-30858 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Apple iOS, iPadOS, and macOS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-30858?
CVE-2021-30858 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.
Which products are affected by CVE-2021-30858?
CVE-2021-30858 affects Apple iOS, iPadOS, and macOS. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-30858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-30858, 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

Explore the affected products and dependency analysis for CVE-2021-30858

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