CVE-2021-30858

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, nvd
Trending — 4 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: 13%CVSS: 8.8Exploit: cisa kev · ssvc active · epss top5pctExposed services: Not assessed

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
9.0CRITICALhigh 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
13%
EPSS %ILE
96th
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

August 24, 2021

Last Modified

October 27, 2025

Advisory Details (10)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. Patch available.
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) @ hirsute2026-10-04ubuntu
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.

Affected Packages

(9 across 5 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk2.32.3-1, 2.32.4-1~deb10u12.32.4-1~deb11u1—
wpewebkit2.32.3-22.32.4-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.4-1—
wpewebkit—2.32.4-1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.4-1—
wpewebkit—2.32.4-1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.4-1—
wpewebkit—2.32.4-1—
Debian:10(1)
PackageVulnerable rangeFixed inDependents
webkit2gtk2.24.2-1 ... 2.32.3-1~deb10u1 (87 versions)2.32.4-1~deb10u1—

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 60× in last 7d / 264× 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 1,077 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2021-30858?
CVE-2021-30858 is a critical 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 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 attention. A fix is available. Apply it.
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 (CRITICAL).
Which products are affected by CVE-2021-30858?
CVE-2021-30858 affects Apple iOS, iPadOS, and macOS. The affected packages EchelonGraph has on record, with version ranges, are listed in the Affected Packages section of this page.
How do I remediate CVE-2021-30858?
A fix for CVE-2021-30858 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-30858 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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