CVE-2021-30661

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 — 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: 4.5%CVSS: 8.8Exploit: cisa kev · ssvc activeExposed 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 Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. 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
4.5%
EPSS %ILE
91st
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

September 8, 2021

Last Modified

October 23, 2025

Advisory Details (6)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. Patch available.
generic🔴 Active Exploitation

About the security content of watchOS 7.4 - Apple Support

https://support.apple.com/en-us/HT212324
generic🔴 Active Exploitation

About the security content of tvOS 14.5 - Apple Support

https://support.apple.com/en-us/HT212323
generic🔴 Active Exploitation

About the security content of Safari 14.1 - Apple Support

https://support.apple.com/en-us/HT212318
generic🔴 Active Exploitation

About the security content of iOS 14.5 and iPadOS 14.5 - Apple Support

https://support.apple.com/en-us/HT212317
generic🔴 Active Exploitation

About the security content of iOS 12.5.3 - Apple Support

https://support.apple.com/en-us/HT212341
generic🔴 Active Exploitation

About the security content of macOS Big Sur 11.3 - Apple Support

https://support.apple.com/en-us/HT212325

Vendor Advisories for CVE-2021-30661(1)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatwebkitgtk4-0:2.48.3-2.el7_92025-07-07redhat
redhatwebkit2gtk3-0:2.30.4-1.el82021-05-18redhat

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 rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.30.1-1: fixed in 2.30.1-1
—
wpewebkit—
  • every version up to 2.30.0-1: fixed in 2.30.0-1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.30.1-1: fixed in 2.30.1-1
—
wpewebkit—
  • every version up to 2.30.0-1: fixed in 2.30.0-1
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.30.1-1: fixed in 2.30.1-1
—
wpewebkit—
  • every version up to 2.30.0-1: fixed in 2.30.0-1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.30.1-1: fixed in 2.30.1-1
—
wpewebkit—
  • every version up to 2.30.0-1: fixed in 2.30.0-1
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.24.2-1 ... 2.30.2-1 (67 versions)
  • every version up to 2.30.3-1~deb10u1: fixed in 2.30.3-1~deb10u1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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 93× in last 7d / 402× 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 1,679 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(6)

What is CVE-2021-30661?
CVE-2021-30661 is a critical vulnerability published on September 8, 2021. A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report…
When was CVE-2021-30661 disclosed?
CVE-2021-30661 was first published on September 8, 2021, 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-2021-30661 actively exploited?
Yes. CISA added CVE-2021-30661 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Apple Multiple Products. 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-2021-30661?
CVE-2021-30661 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-2021-30661?
CVE-2021-30661 affects Apple Multiple Products. 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-2021-30661?
A fix for CVE-2021-30661 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-30661 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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