CVE-2021-21146Network attack vector

Sandbox escape via Navigation use-after-free

Published Feb 9, 2021 · Updated Aug 3, 2024

Use after free in Navigation in Google Chrome before 88.0.4324.146 allows remote attackers to escape the sandbox via crafted HTML. Public records identify the Navigation component but do not disclose the freed object or the operation that later dereferences it. Exploitation requires a compromised renderer process and user interaction with the crafted page; success escapes the renderer sandbox.

CVSS severity9.6
Critical
EPSS probability1.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use after free in Navigation in Google Chrome before 88.0.4324.146 allows remote attackers to escape the sandbox via crafted HTML. Public records identify the Navigation component but do not disclose the freed object or the operation that later dereferences it. Exploitation requires a compromised renderer process and user interaction with the crafted page; success escapes the renderer sandbox.

The record

CVE
CVE-2021-21146
Published
Feb 9, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-416, T1068
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <88.0.4324.146

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <88.0.4324.146

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
9.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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
T1068Exploitation for Privilege Escalation

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

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Your stack

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