CVE-2020-26186

SMM code execution via RuntimeServices overwrite

Published Jan 8, 2021 · Updated Sep 17, 2024

Code execution in Dell Inspiron 5675 BIOS before 1.4.1 allows local users to execute arbitrary code in System Management Mode via system-memory access. The firmware accepts attacker-controlled overwrites of the UEFI RuntimeServices structure, redirecting runtime service execution into attacker-supplied code. Physical access and the ability to write system memory are required; successful exploitation can compromise firmware confidentiality, integrity, and availability.

CVSS severity6.8
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code execution in Dell Inspiron 5675 BIOS before 1.4.1 allows local users to execute arbitrary code in System Management Mode via system-memory access. The firmware accepts attacker-controlled overwrites of the UEFI RuntimeServices structure, redirecting runtime service execution into attacker-supplied code. Physical access and the ability to write system memory are required; successful exploitation can compromise firmware confidentiality, integrity, and availability.

The record

CVE
CVE-2020-26186
Published
Jan 8, 2021
Updated
Sep 17, 2024
Vendor
Dell
Product
Dell Client Platform BIOS
Classifications
CWE-668, CWE-642, T1542.001
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=unspecified <1.4.1

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Dell · Dell Client Platform BIOSversion=unspecified <1.4.1

Published CVSS scores

7.2NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
6.8DellCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposed Resource to Wrong Sphere
CWE-642External Control of Critical State Data
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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