CVE-2021-21806

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. The victim needs to visit a malicious web site to trigger the vulnerability.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: Track

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
Severity88% × 45%
Exploitation3% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
3%
EPSS %ILE
85%
KEV
Not listed

Published

July 8, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Aug 18, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

TALOS-2020-1214 || Cisco Talos Intelligence Group - Comprehensive Threat Intelligence

https://talosintelligence.com/vulnerability_reports/TALOS-2020-1214
generic🔴 Active Exploitation

oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2021-0004

http://www.openwall.com/lists/oss-security/2021/07/23/1

Vendor Advisories for CVE-2021-21806(2)

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 / EcosystemFixed in / PatchReleasedSource
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—2.30.6-1—
wpewebkit—2.30.6-1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.30.6-1—
wpewebkit—2.30.6-1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.30.6-1—
wpewebkit—2.30.6-1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
webkit2gtk—2.30.6-1—
wpewebkit—2.30.6-1—
Debian:10(1)
PackageVulnerable rangeFixed inDependents
webkit2gtk2.24.2-1 ... 2.30.5-1~deb10u1 (74 versions)2.30.6-1~deb10u1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 31× 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 130 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-21806?
CVE-2021-21806 is a high vulnerability published on July 8, 2021. An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. The victim needs to visit a malicious web site to trigger the vulnerability.
When was CVE-2021-21806 disclosed?
CVE-2021-21806 was first published in the National Vulnerability Database on July 8, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-21806 actively exploited?
CVE-2021-21806 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 14.6% of all scored CVEs.
What is the CVSS score of CVE-2021-21806?
CVE-2021-21806 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-21806?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21806, 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

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