CVE-2025-56425

CriticalPublic PoCRCE

Published: 08 January 2026

Published

08 January 2026

Modified

23 January 2026

KEV Added

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Patch

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CVSS Score 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Score 0.0036 58.5th percentile

Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-56425 is a critical-severity Command Injection (CWE-77) vulnerability in Optimal-Systems Enaio. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 41.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) 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-10 Information Input Validation good match

prevent

Directly requires input validation at the /osrest/api/organization/sendmail endpoint to prevent injection of arbitrary SMTP commands.

SI-9 Information Input Restrictions good match

prevent

Enforces restrictions on inputs to the vulnerable API endpoint, blocking crafted payloads that enable SMTP command injection.

SI-2 Flaw Remediation good match

prevent

Mandates timely flaw remediation, including patching the command injection vulnerability in affected AppConnector versions.

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?

The vulnerability is a command injection in a public-facing REST API endpoint (/osrest/api/organization/sendmail) exploitable remotely over the network (AV:N/AC:L/PR:N), directly enabling T1190: Exploit Public-Facing Application.

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

NVD Description

An issue was discovered in the AppConnector component version 10.10.0.183 and earlier of enaio 10.10, in the AppConnector component version 11.0.0.183 and earlier of enaio 11.0, and in the AppConnctor component version 11.10.0.183 and earlier of enaio 11.10. The vulnerability…

allows authenticated remote attackers to inject arbitrary SMTP commands via crafted input to the /osrest/api/organization/sendmail endpoint

Deeper analysisAI

CVE-2025-56425 is a command injection vulnerability (CWE-77) discovered in the AppConnector component of enaio software. It affects AppConnector version 10.10.0.183 and earlier in enaio 10.10, version 11.0.0.183 and earlier in enaio 11.0, and version 11.10.0.183 and earlier in enaio 11.10. The flaw enables authenticated remote attackers to inject arbitrary SMTP commands by supplying crafted input to the /osrest/api/organization/sendmail endpoint. Published on 2026-01-08, it carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

Authenticated remote attackers can exploit this vulnerability over the network with low attack complexity and no user interaction. By sending malicious payloads to the specified endpoint, they can inject and execute arbitrary SMTP commands, potentially compromising confidentiality and availability to a high degree as indicated by the CVSS metrics.

Advisories and mitigation details are available in references including the analysis at https://mind-bytes.de/smtp-injection-in-enaio-component-appconnector-cve-2025-56425/ and the vendor site at https://www.optimal-systems.de/enaio. Security practitioners should consult these for patching instructions and workarounds specific to affected enaio deployments.