CVE-2023-28026

Memory disclosure via unchecked UEFI variable size

Published Jun 23, 2023 · Updated Dec 4, 2024

Improper input validation in Dell Client Platform BIOS allows local users with administrator privileges to modify a UEFI variable. The Setup DXE module reuses a size returned by GetVariable when SetVariable copies fixed stack buffers, exposing adjacent memory in NVRAM. Administrator-level local access is required; the direct result is disclosure of stack or global memory and alteration of firmware variables.

CVSS severity5.1
Medium
EPSS probability0.17%
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 Dell Client Platform BIOS allows local users with administrator privileges to modify a UEFI variable. The Setup DXE module reuses a size returned by GetVariable when SetVariable copies fixed stack buffers, exposing adjacent memory in NVRAM. Administrator-level local access is required; the direct result is disclosure of stack or global memory and alteration of firmware variables.

The record

CVE
CVE-2023-28026
Published
Jun 23, 2023
Updated
Dec 4, 2024
Vendor
Dell
Product
Dell Client Platform BIOS
Classifications
CWE-20, T1542.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 4, 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=All Versions

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Dell · Dell Client Platform BIOSversion=All Versions

Published CVSS scores

5.1DellCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:L

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1542.001Pre-OS Boot: System Firmware

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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