CVE-2026-9977Network attack vector

Sandbox escape via insufficient WebShare validation

Published May 28, 2026 · Updated May 28, 2026

Improper input validation in WebShare in Google Chrome on Android before 148.0.7778.216 allows remote attackers to escape the sandbox. WebShare accepts attacker-controlled data from a crafted HTML page without sufficient validation, but Google has not disclosed the affected operation. Exploitation requires user interaction and control of a compromised renderer process; escaping the sandbox exposes resources outside that renderer.

CVSS severity8.3
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in WebShare in Google Chrome on Android before 148.0.7778.216 allows remote attackers to escape the sandbox. WebShare accepts attacker-controlled data from a crafted HTML page without sufficient validation, but Google has not disclosed the affected operation. Exploitation requires user interaction and control of a compromised renderer process; escaping the sandbox exposes resources outside that renderer.

The record

CVE
CVE-2026-9977
Published
May 28, 2026
Updated
May 28, 2026
Vendor
Go standard library
Product
Google Chrome
Classifications
CWE-20, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 28, 2026CVE publishedPublication date reported by the CVE source.
  2. May 28, 2026Record 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=148.0.7778.216 <148.0.7778.216

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · Google Chromeversion=148.0.7778.216 <148.0.7778.216

Published CVSS scores

8.3CISA-ADPCVSS:3.1/AV:N/AC:H/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-20Improper Input Validation
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

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Your stack

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