CVE-2024-21640Public exploitNetwork attack vector

Sandbox memory disclosure via pixel-format mismatch

Published Jan 13, 2024 · Updated Jun 17, 2025

Out-of-bounds read in CEF before commit 1f55d2e allows attackers to read memory outside the GPU sandbox via a malicious frame. OnFrameCaptured sizes shared memory using the supplied pixel format, but OnPaint treats the buffer as ARGB; UNKNOWN returns zero and lets an undersized buffer pass. Exploitation requires a compromised GPU process and off-screen rendering, exposing adjacent memory and potentially crashing the host application.

CVSS severity9.6
Critical
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in CEF before commit 1f55d2e allows attackers to read memory outside the GPU sandbox via a malicious frame. OnFrameCaptured sizes shared memory using the supplied pixel format, but OnPaint treats the buffer as ARGB; UNKNOWN returns zero and lets an undersized buffer pass. Exploitation requires a compromised GPU process and off-screen rendering, exposing adjacent memory and potentially crashing the host application.

The record

CVE
CVE-2024-21640
Published
Jan 13, 2024
Updated
Jun 17, 2025
Vendor
Chromium Embedded Framework
Product
Chromium Embedded Framework (CEF)
Classifications
CWE-125, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2025Record 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=< commit 1f55d2e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Chromium Embedded Framework · Chromium Embedded Framework (CEF)version=< commit 1f55d2e

Published CVSS scores

9.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H
5.4GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1068Exploitation for Privilege Escalation

Public exploit references

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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