CVE-2026-9951Network attack vectorHinoki check available

Sandbox escape via UI use after free

Published May 28, 2026 · Updated May 28, 2026

Use after free in the UI of Google Chrome before 148.0.7778.216 allows remote attackers to escape the sandbox via a crafted HTML page. Google identifies the UI subsystem but has not disclosed the affected function, object lifetime error, or triggering UI operation. Exploitation requires a user to open attacker-controlled HTML in a vulnerable browser; the published record establishes no more specific trigger.

CVSS severity8.3
High
EPSS probability0.22%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use after free in the UI of Google Chrome before 148.0.7778.216 allows remote attackers to escape the sandbox via a crafted HTML page. Google identifies the UI subsystem but has not disclosed the affected function, object lifetime error, or triggering UI operation. Exploitation requires a user to open attacker-controlled HTML in a vulnerable browser; the published record establishes no more specific trigger.

The record

CVE
CVE-2026-9951
Published
May 28, 2026
Updated
May 28, 2026
Vendor
WebM Project
Product
Chrome
Classifications
CWE-416, T1189
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 version<148.0.7778.216

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WebM Project · Chrome<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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 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
T1189Drive-by Compromise

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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