CVE-2026-2999

Critical

Published: 02 March 2026

Published

02 March 2026

Modified

09 March 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0009 25.5th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-2999 is a critical-severity Download of Code Without Integrity Check (CWE-494) vulnerability in Changingtec Idexpert. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-7 (Boundary Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly mitigates the RCE vulnerability by requiring timely remediation through patching the flaw in the IDExpert Windows Logon Agent as per vendor advisories.

SC-7 Boundary Protection good match

prevent

Prevents unauthenticated remote attackers from reaching the vulnerable logon agent service by monitoring and controlling communications at system boundaries.

SI-3 Malicious Code Protection good match

preventdetect

Blocks or detects the arbitrary executable files downloaded and executed by the vulnerability through malicious code protection mechanisms like antivirus scanning.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Unauthenticated remote code execution vulnerability in a network-exposed Windows service (Logon Agent) enables exploitation of a public-facing application to download and execute arbitrary code.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

IDExpert Windows Logon Agent developed by Changing has a Remote Code Execution vulnerability, allowing unauthenticated remote attackers to force the system to download arbitrary executable files from a remote source and execute them.

Deeper analysisAI

CVE-2026-2999 is a Remote Code Execution vulnerability affecting the IDExpert Windows Logon Agent developed by Changing. Published on 2026-03-02T07:16:22.743, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-494. The flaw enables unauthenticated remote attackers to force affected systems to download arbitrary executable files from a remote source and execute them.

Unauthenticated attackers can exploit this vulnerability remotely over the network with low attack complexity, requiring no privileges or user interaction. Successful exploitation grants high-impact access to confidentiality, integrity, and availability, allowing arbitrary code execution on the target system.

Mitigation details are outlined in advisories from the vendor at https://www.changingtec.com/news_detail.jsp?item_id=348 and from TWCERT at https://www.twcert.org.tw/en/cp-139-10741-daed4-2.html and https://www.twcert.org.tw/tw/cp-132-10740-b2eb2-1.html.