CVE-2021-30551

Exploited in the Wild ✓ Confirmed 0-Day ★ Google Project Zero
Triaged: March 5, 2026 18 articles
VulnLookup ↗ NVD ↗ MITRE ↗ Advisory ↗ P0 Sheet ↗ CISA KEV ↗

EPSS Score

Source: FIRST.org · 2026-05-24
82.22%
probability
This CVE has a 82.22% probability of being exploited in the next 30 days.
0% Top 99.2th percentile of all CVEs 100%
CVSS score unavailable
Neither CIRCL nor NVD returned a CVSS score for this CVE. View on VulnerabilityLookup ↗

Description

Project Zero
Type confusion in v8

Attack Intelligence

Google Project Zero

Discovered
June 3, 2021
Patched
June 9, 2021
Reported by
Clement Lecigne of Google's Threat Analysis Group and Sergei Glazunov of Google Project Zero
Root Cause Analysis
https://googleprojectzero.github.io/0days-in-the-wild/0day-RCAs/2021/CVE-2021-30551.html
Update Google Chrome ASAP to Patch 2 New Actively Exploited Zero-Day Flaws
TheHackerNews
Google pushes emergency Chrome update to fix zero-day used in attacks
BleepingComputer Dec 13, 2021
Emergency Google Chrome update fixes zero-days used in attacks
BleepingComputer Oct 28, 2021
Update Google Chrome to Patch New Zero-Day Exploit Detected in the Wild
TheHackerNews
Google patches 8th Chrome zero-day exploited in the wild this year
BleepingComputer Jul 16, 2021
Google pushes emergency Chrome update to fix two zero-days
BleepingComputer Sep 30, 2021
Google: Russian SVR hackers targeted LinkedIn users with Safari zero-day
BleepingComputer Jul 14, 2021
Google Details iOS, Chrome, IE Zero-Day Flaws Exploited Recently in the Wild
TheHackerNews
Urgent Chrome Update Released to Patch Actively Exploited Zero-Day Vulnerability
TheHackerNews
Google Chrome emergency update fixes zero-day exploited in attacks
BleepingComputer Feb 14, 2022
Update Your Chrome Browser to Patch New Zero‑Day Bug Exploited in the Wild
TheHackerNews
Emergency Google Chrome update fixes zero-day exploited in the wild
BleepingComputer Sep 24, 2021
Google patches 10th Chrome zero-day exploited in the wild this year
BleepingComputer Sep 13, 2021
Google fixes seventh Chrome zero-day exploited in the wild this year
BleepingComputer Jun 17, 2021
Google fixes sixth Chrome zero-day exploited in the wild this year
BleepingComputer Jun 09, 2021
Update‌ ‌Your Chrome Browser to Patch Yet Another 0-Day Exploit‌ed ‌in‌-the‌-Wild
TheHackerNews
Israeli Firm Helped Governments Target Journalists, Activists with 0-Days and Spyware
TheHackerNews
Qualys Response to CISA Alert: Binding Operational Directive 22-01
Qualys Nov 09, 2021

Signal Intelligence

Confidenceⓘ
95%
EPSS 82.22%
Mentions 18
Last Seen Feb 14, 2022

CNA Information

Analyst Note

Auto-imported from Google Project Zero — confirmed zero-day by definition.

Threat Actors 1

Tortoiseshell
apt_group Information theft and espionage 🇮🇷 IR

Triage Info

Decided atMar 05, 2026