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CVE-2026-40551NVD status: Deferred

mpGabinet: Use of Client-Side Authentication

CVE-2026-40551 is a high-severity use of client-side authentication vulnerability in mpGabinet from BinSoft, with a CVSS 4.0 base score of 8.4 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected mpGabinet versions: 23.12.19 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of mpGabinet you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
BinSoftmpGabinet23.12.19 and earlierNot stated
BinSoftmpFirma26.4.9 and earlierNot stated
BinSoftmpFaktura26.4.9 and earlierNot stated
BinSoftmpFirma ERP26.4.9 and earlierNot stated
BinSoftmpSekretariat25.2.4 and earlierNot stated
BinSoftmpPOS25.2.4 and earlierNot stated
BinSoftmpCRM25.2.4 and earlierNot stated
BinSoftmpWarsztat20.4.28 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
LowLimited loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (cert.pl).

Official description

Multiple BinSoft products perform 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. The described issue affects all published versions. The vendor stated that this issue is a direct result of the architecture model in which the software is distributed, and that it will be mitigated with a corrected installation manual.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Client-Side Authentication

A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.

How developers prevent this class of flaw

  • Do not rely on client side data. Always perform server side authentication.

More Use of Client-Side Authentication vulnerabilities (CWE-603)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Client-Side Authentication vulnerabilities

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