CVE-2023-26246Public exploit

Custom firmware installation via patched signature branch

Published Apr 27, 2023 · Updated Jan 31, 2025

Improper authorization in Hyundai Gen5W_L firmware AE_E_PE_EUR.S5W_L001.001.211214 allows local users to install custom firmware. A modified AppUpgrade binary changes the conditional signature-validation branch from JZ to JMP, continuing installation when file signatures are invalid. Low-privileged local access to the firmware installation path is required, and successful exploitation replaces trusted IVI software.

CVSS severity7.8
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Hyundai Gen5W_L firmware AE_E_PE_EUR.S5W_L001.001.211214 allows local users to install custom firmware. A modified AppUpgrade binary changes the conditional signature-validation branch from JZ to JMP, continuing installation when file signatures are invalid. Low-privileged local access to the firmware installation path is required, and successful exploitation replaces trusted IVI software.

The record

CVE
CVE-2023-26246
Published
Apr 27, 2023
Updated
Jan 31, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-863, T1601.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8CISACVSS:3.1/AV:L/AC:L/PR:L/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.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1601.001Patch System Image

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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