CVE-2026-12027Network attack vector

Sandbox escape via unmarked hidden target process

Published Jun 11, 2026 · Updated Jun 11, 2026

Sandbox escape in Google Chrome before 149.0.7827.115 allows remote attackers with a compromised renderer to cross the sandbox via crafted HTML. The Headless target handler creates a hidden target but fails to mark its associated renderer process as used, unlike regular Chrome. Exploitation requires prior renderer compromise and user interaction with the page; successful escape permits code to affect the host context beyond the renderer sandbox.

CVSS severity9.6
Critical
EPSS probability0.22%
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

Sandbox escape in Google Chrome before 149.0.7827.115 allows remote attackers with a compromised renderer to cross the sandbox via crafted HTML. The Headless target handler creates a hidden target but fails to mark its associated renderer process as used, unlike regular Chrome. Exploitation requires prior renderer compromise and user interaction with the page; successful escape permits code to affect the host context beyond the renderer sandbox.

The record

CVE
CVE-2026-12027
Published
Jun 11, 2026
Updated
Jun 11, 2026
Vendor
Go standard library
Product
Google Chrome
Classifications
CWE-693, CWE-250, T1203
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 11, 2026Record 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=149.0.7827.115 <149.0.7827.115

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Go standard library · Google Chromeversion=149.0.7827.115 <149.0.7827.115

Published CVSS scores

9.6CISA-ADPCVSS: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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
CWE-250Execution with Unnecessary Privileges
T1203Exploitation for Client Execution

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