CVE-2026-40639Public exploit

Privilege escalation via recoverable BIOS passwords

Published Jun 9, 2026 · Updated Jun 9, 2026

Weak password encoding in Dell Client Platform BIOS allows physically proximate attackers to recover BIOS passwords from SPI flash. The SystemPwSmm driver stores administrator and user passwords in 32-byte DVAR records using a 20-byte repeating XOR key; null padding exposes the key and enables deterministic plaintext recovery. Reading the SPI flash requires physical access or an attacker-controlled boot environment, after which the recovered password grants BIOS access and permits security-setting changes.

CVSS severity5.7
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Weak password encoding in Dell Client Platform BIOS allows physically proximate attackers to recover BIOS passwords from SPI flash. The SystemPwSmm driver stores administrator and user passwords in 32-byte DVAR records using a 20-byte repeating XOR key; null padding exposes the key and enables deterministic plaintext recovery. Reading the SPI flash requires physical access or an attacker-controlled boot environment, after which the recovered password grants BIOS access and permits security-setting changes.

The record

CVE
CVE-2026-40639
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Dell Technologies
Product
Latitude 5424 Rugged
Classifications
CWE-261, T1555
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=0 <1.42.0

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Dell Technologies · Latitude 5424 Ruggedversion=0 <1.42.0
Dell Technologies · Dell Embedded Box PC 3000version=0 <1.32.0
Dell Technologies · Precision 3630 Towerversion=0 <2.40.0
Dell Technologies · Dell Embedded Box PC 5000version=0 <1.33.0
Dell Technologies · Precision 3930 Rackversion=0 <2.43.0
Dell Technologies · Latitude 7424 Rugged Extremeversion=0 <1.42.0
Dell Technologies · Dell Edge Gateway 5000version=0 <1.36.0
Dell Technologies · Dell Edge Gateway 3000 Seriesversion=0 <1.26.0
Dell Technologies · Latitude 7220 Rugged Extreme Tabletversion=0 <1.51.0
Dell Technologies · Latitude 5420 Ruggedversion=0 <1.42.0
Dell Technologies · Latitude 7220EX Rugged Extreme Tabletversion=0 <1.51.0

Published CVSS scores

5.7Dell TechnologiesCVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-261Weak Encoding for Password
T1555Credentials from Password Stores

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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