CVE-2021-30557Network attack vector

Extension-assisted heap corruption via freed TabGroups object access

Published Jul 2, 2021 · Updated Aug 3, 2024

Use-after-free in TabGroups in Google Chrome before 91.0.4472.114 allows context-dependent attackers to corrupt heap memory. The TabGroups component accesses an object after its storage has been released, but Google has not disclosed the specific object or lifetime transition. Exploitation requires a user to install an attacker-controlled extension and load a crafted HTML page, enabling heap corruption within the browser process.

CVSS severity8.8
High
EPSS probability11.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in TabGroups in Google Chrome before 91.0.4472.114 allows context-dependent attackers to corrupt heap memory. The TabGroups component accesses an object after its storage has been released, but Google has not disclosed the specific object or lifetime transition. Exploitation requires a user to install an attacker-controlled extension and load a crafted HTML page, enabling heap corruption within the browser process.

The record

CVE
CVE-2021-30557
Published
Jul 2, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-416, T1176.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <91.0.4472.114

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <91.0.4472.114

Published CVSS scores

6.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1176.001Browser Extensions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo