Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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ReconObtain local system access
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DeliveryLaunch mpGabinet client
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ExploitReverse engineer authentication routine
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InstallPatch binary verification logic
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C2Execute modified client
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ExecutePresent as arbitrary user
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ImpactAccess privileged data
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V6 - Authentication Use of client-side authentication
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| Exploitation Conditions | Attacker must have existing local access to a system where mpGabinet client application is installed, with sufficient privileges to execute the application (PR:L in CVSS 4.0 indicates low-privilege user access is sufficient). Attacker must be able to modify the mpGabinet application binary, either through write access to the installation directory or by running a modified copy from a user-writable location. The vulnerable client must be able to connect to the mpGabinet backend server. No special server-side configuration or enabled features are required-the vulnerability is inherent to the client-side authentication architecture affecting all default deployments. The local attack vector (AV:L) limits exploitation to scenarios involving insider threats, compromised endpoints, or attackers who have gained initial access through other vulnerabilities (using this as a privilege escalation or lateral movement technique within mpGabinet's authorization model). Remote exploitation is not possible without first compromising a system running the client application. |
| Impact | The CVSS 4.0 score of 8.4 reflects high confidentiality and integrity impact (VC:H/VI:H) with low availability impact (VA:L), but the AV:L (local attack vector) and PR:L (low privileges required) significantly constrain real-world exploitation scenarios. This is not a remote unauthenticated vulnerability-the attacker must already have legitimate local access to a system running mpGabinet and possess sufficient privileges to execute and potentially modify binaries. However, once these prerequisites are met, attack complexity is low (AC:L) and no user interaction is needed (UI:N), making exploitation straightforward for an insider threat or an attacker who has gained initial access through other means. The lack of scope change (SC:N/SI:N/SA:N) indicates the vulnerability is confined to the application's security context. No EPSS data is available as this is a 2026 CVE, and CISA KEV status is negative, suggesting no confirmed widespread or targeted exploitation. The primary risk is in environments where mpGabinet handles sensitive data and where insider threats or lateral movement scenarios are realistic concerns. Organizations should prioritize remediation based on whether mpGabinet is deployed on shared systems, handles privileged operations, or stores data requiring strong access controls. The fundamental architectural flaw (client-side authentication) means partial mitigations are ineffective-only a complete redesign moving authentication server-side provides genuine security. |
| Exploit ScenarioDerived | An attacker with a legitimate low-privilege mpGabinet account on a shared workstation uses a hex editor or debugger to locate the authentication verification routine in the mpGabinet executable, then patches the binary to always return authentication success regardless of credentials entered. Upon launching the modified client and connecting to the backend server, the attacker presents themselves as an administrative user, gaining access to sensitive patient records, financial data, or system configuration that their original low-privilege account should not access. Because authentication enforcement occurs entirely client-side, the server accepts the compromised client's claims without independent verification. |
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Alert meAnalysisAIv1 – Apr 28, 2026
Client-side authentication bypass in mpGabinet 23.12.19 and earlier allows local authenticated attackers to impersonate arbitrary users by patching the application binary. An attacker with legitimate low-privilege access to the system can manipulate the compiled application code to skip login verification entirely, gaining unauthorized access as any user including administrators. EPSS score not available for this 2026 CVE; no active exploitation or public POC confirmed at time of analysis.
RemediationAI
Upgrade to mpGabinet version later than 23.12.19 if a patched release is available-check the vendor website at https://www.mpgabinet.pl/ and the CERT-PL advisory at https://cert.pl/posts/2026/04/CVE-2026-40550/ for update announcements, though no specific fix version is confirmed in available data at time of analysis. Because this is an architectural vulnerability (CWE-603), effective remediation requires the vendor to redesign authentication to enforce all verification server-side rather than client-side. Until a patched version with server-enforced authentication is deployed, implement strict compensating controls: restrict local access to systems running mpGabinet to only fully trusted users through OS-level access controls and group policies; deploy application whitelisting or integrity monitoring solutions (Windows Defender Application Control, AppLocker, HIDS) to detect unauthorized binary modifications; implement file system permissions preventing non-administrative users from writing to the mpGabinet installation directory; enable audit logging for all mpGabinet authentication events and cross-reference with backend server logs to detect anomalies indicating bypassed authentication. Note that these mitigations only raise the bar for exploitation-they do not eliminate the underlying vulnerability. Organizations handling sensitive data should consider migrating to alternative solutions with server-enforced authentication if vendor patch timeline is uncertain.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
The vulnerability stems from CWE-603 (Use of Client-Side Authentication), a fundamental architectural flaw where security-critical authentication logic resides in the client application rather than being enforced server-side. In mpGabinet, the login verification process executes within the local application binary, making it susceptible to reverse engineering and binary patching. An attacker can use tools like hex editors, debuggers, or binary patchers to modify the compiled code-such as changing conditional jump instructions, NOP-ing out authentication checks, or hardcoding success values-to bypass the verification routine. Because the backend server trusts the client's assertion of authenticated status rather than independently validating credentials, the compromised client can present itself as any user. This design pattern violates the principle that clients are untrusted and all security enforcement must occur server-side. The CPE cpe:2.3:a:binsoft:mpgabinet identifies the vendor as Binsoft and confirms this is an application-layer vulnerability affecting all instances of the software.
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Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
Primary rating from Vendor (CERT-PL) · only source for this CVE.
CVSS VectorVendor: CERT-PL
Lifecycle Timeline
2DescriptionCVE.org
mpGabinet performs client-side authentication. An attacker with access to any application instance connected to the backend server can bypass the login verification process by manipulating the application binary and authenticate as an arbitrary user.
This issue affects mpGabinet version 23.12.19 and below.
Executive ViewAI
CVE-2026-40551 affects mpGabinet 23.12.19 and earlier, enabling authenticated local users to bypass authentication controls and assume administrative privileges by modifying application binaries. Organizations running vulnerable versions face insider threat risk where legitimate low-privilege employees could escalate to full system administrator access without detection.
No vendor-released patch identified at time of analysis. Interim mitigations: (1) Implement file integrity monitoring on mpGabinet binaries using host-based tools; (2) Restrict file system write access to application directories via NTFS/filesystem ACLs to administrators only; (3) Enable application whitelisting to prevent unauthorized binary modifications; (4) Enforce multi-factor authentication at network/directory service level as compensating control for application-layer bypass; (5) Monitor for suspicious binary modifications via endpoint detection and response (EDR) tools; (6) Limit low-privilege user access to systems running mpGabinet until patch is available.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
mpGabinet 23.12.19 and earlier suffers from privilege escalation due to excessive database privileges assigned to the ap
Remote command execution in mpGabinet 23.12.19 and below allows authenticated database administrators or unauthenticated
EUVD-2026-26045
NVD
CVE.org
EPSS
Vulnrichment
VulDB
GitHub PoC
Exploit-DB