CVE-2021-21220

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 — 5 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: 69%CVSS: 8.8Exploit: cisa kev · ssvc active · Metasploit · epss top5pct · epss high · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

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 PROB
69%
EPSS %ILE
99%
KEV
⚠ Exploited

Published

April 26, 2021

Last Modified

October 24, 2025

Advisory Details (8)

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

Packet Storm

http://packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitrary-Code-Execution.html
generic

Packet Storm

http://packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-Out-Of-Bounds-Access-Remote-Code-Execution.html
generic

Chromium, Google Chrome: Multiple vulnerabilities (GLSA 202104-08) — Gentoo security

https://security.gentoo.org/glsa/202104-08
generic

[SECURITY] Fedora 34 Update: chromium-90.0.4430.93-1.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/
generic

[SECURITY] Fedora 33 Update: chromium-90.0.4430.93-1.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/
generic

[SECURITY] Fedora 32 Update: chromium-90.0.4430.93-1.fc32 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/
generic
https://crbug.com/1196683
generic🔴 Active Exploitation

Chrome Releases: Stable Channel Update for Desktop

https://chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop.html

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
chromium—90.0.4430.72-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
chromium—90.0.4430.72-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
chromium—90.0.4430.72-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
chromium—90.0.4430.72-1—

Weakness Classification(2)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 92× in last 7d / 344× 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 1,017 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitexploit/multi/browser/chrome_cve_2021_21220_v8_insufficient_validation✓ verified
    First seen Apr 13, 2021

    Google Chrome versions before 89.0.4389.128 V8 XOR Typer Out-Of-Bounds Access RCE

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2021-21220?
CVE-2021-21220 is a critical vulnerability published on April 26, 2021. Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
When was CVE-2021-21220 disclosed?
CVE-2021-21220 was first published in the National Vulnerability Database on April 26, 2021, with the most recent update on October 24, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-21220 actively exploited?
Yes. CISA added CVE-2021-21220 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Google Chromium V8. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-21220?
CVE-2021-21220 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-2021-21220?
CVE-2021-21220 affects Google Chromium V8. 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-2021-21220?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21220, 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-2021-21220

Explore →

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