CVE-2021-30555
ENISA EUVD: EUVD-2021-17476 ↗
✓ Confirmed 0-Day
Triaged: March 20, 2026
1 article
Published: 2021-07-02
EPSS Score
Source: FIRST.org · 2026-05-23
0.29%
probability
This CVE has a 0.29% probability
of being exploited in the next 30 days.
0%
Top 52.3th percentile of all CVEs
100%
CVSS v3.1
Source: NVD8.8
HIGH
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v2 (legacy)
6.8
MEDIUM
Access Vector
Network
Access Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
Description
VulnerabilityLookup (CNA)Use after free in Sharing in Google Chrome prior to 91.0.4472.114 allowed an attacker who convinced a user to install a malicious extension to potentially exploit heap corruption via a crafted HTML page and user gesture.
Affected Products
Google
Chrome
unspecified
Attack Intelligence
CWE-118
· Incorrect Access of Indexable Resource ('Range Error')
CWE-119
· Buffer Overflow
CWE-416
· Use After Free
CWE-664
· Improper Control of a Resource Through its Lifetime
CWE-666
· Operation on Resource in Wrong Phase of Lifetime
CWE-672
· Operation on a Resource after Expiration or Release
CWE-825
· Expired Pointer Dereference
https://crbug.com/1215029
x_refsource_MISC
https://security.gentoo.org/glsa/202107-06
vendor-advisory
x_refsource_GENTOO
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/
vendor-advisory
x_refsource_FEDORA
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/
vendor-advisory
x_refsource_FEDORA
Signal Intelligence
Confidence
85%
EPSS
0.29%
CVSS v3.1
8.8
Mentions
1
Last Seen
Jun 17, 2021
CNA Information
CNA Assigner
Chrome
Analyst Note
CVE-2021-30555 is explicitly named as a Chrome zero-day exploited in the wild in 2021 by BleepingComputer, which is an authoritative source. The article title confirms this is one of seven zero-days Google patched that year with documented active exploitation.
Triage Info
Decided atMar 20, 2026
Published DateJul 02, 2021