CVE-2021-1871

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 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 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 7%CVSS: 9.8Exploit: cisa kev · ssvc activeExposed: 0

A fix is available — apply it.

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
7%
EPSS %ILE
94%
KEV
⚠ Exploited

Published

April 2, 2021

Last Modified

October 23, 2025

Advisory Details (5)

Auto-updated Sep 17, 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-2021-1871
generic

[SECURITY] [DSA 4923-1] webkit2gtk security update

https://www.debian.org/security/2021/dsa-4923
generic🔴 Active Exploitation

About the security content of macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave - Apple Support

https://support.apple.com/en-us/HT212147
generic🔴 Active Exploitation

About the security content of iOS 14.4 and iPadOS 14.4 - Apple Support

https://support.apple.com/en-us/HT212146
generic

[SECURITY] Fedora 33 Update: webkit2gtk3-2.32.0-1.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/

Vendor Advisories for CVE-2021-1871(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuwebkit2gtk-driver (2.32.0-0ubuntu0.20.10.1) @ groovy2026-09-19ubuntu
redhatwebkitgtk4-0:2.48.3-2.el7_92025-07-07redhat
redhatwebkit2gtk3-0:2.32.3-2.el82021-11-09redhat

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
webkit2gtk—2.32.0-2—
wpewebkit—2.32.0-2—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.0-2—
wpewebkit—2.32.0-2—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.0-2—
wpewebkit—2.32.0-2—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.32.0-2—
wpewebkit—2.32.0-2—
Debian:10(1)
PackageVulnerable rangeFixed inDependents
webkit2gtk2.24.2-1 ... 2.32.0-2 (81 versions)2.32.1-1~deb10u1—

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 110× in last 7d / 469× 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 1,682 total refreshes for this CVE.

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

Frequently asked(6)

What is CVE-2021-1871?
CVE-2021-1871 is a critical vulnerability published on April 2, 2021. A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this…
When was CVE-2021-1871 disclosed?
CVE-2021-1871 was first published in the National Vulnerability Database on April 2, 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-2021-1871 actively exploited?
Yes. CISA added CVE-2021-1871 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-2021-1871?
CVE-2021-1871 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2021-1871?
CVE-2021-1871 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-2021-1871?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1871, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-1871

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