CVE-2026-0857

Insufficient Password Hashing in Mesalvo MEONA Exposes Passwords

Published May 20, 2026 CVSS 3.1 · 4.4 Medium EPSS < 1% KEV · Not listed
Description
Use of a Password Hash With Insufficient Computational Effort in Mesalvo MEONA (MEONA Server and MEONA Client) for user accounts whose password was last set under a version before MEONA 2024.10. MEONA versions before 2024.10 protected stored passwords with SHA-1 (versions from October 2015) or stored them without protection (earlier versions). Since MEONA 2024.10 (June 2024) Argon2 is the default method and every password that is set or changed is stored with Argon2; passwords last set under an earlier version keep the earlier method until they are changed. An administrator could in addition select the storage method per account. A MEONA super administrator can read the stored value of such accounts in the user administration of the MEONA Client or export it through administrative database functions. Only accounts managed locally in MEONA are affected; accounts authenticated through the operating hospital's directory service (Active Directory / Entra ID) have no password stored in MEONA. In typical installations end users authenticate through the directory service and local accounts are limited to emergency and technical accounts.
Exploitation requires super administrator permissions in MEONA (or direct access to the MEONA database) from within the operating hospital's network; MEONA is operated exclusively within closed hospital networks without exposure to the public Internet, and where a hospital permits remote access to that network at all, it is only through the hospital's own remote-access infrastructure (e.g. VPN) under the hospital's control. Installations in which every password has been set or changed under MEONA 2024.10 or later are not affected. Mesalvo is not aware of any exploitation outside the reported security test.
This issue affects MEONA Server and MEONA Client in versions 2024.10, 2025.04 and 2026.03 (for accounts with passwords last set under earlier versions). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) remove the legacy storage methods, require every affected account to set a new Argon2-protected password at next logon, and no longer display stored credential values in the user administration. See Mesalvo Security Advisory MSA-2026-002.

Remediation

Vendor Solution

MEONA 2025.04.24 and 2026.03.02 (Q4 2026) remove the legacy password storage methods, require every account whose password is still stored with a legacy method to set a new Argon2-protected password at next logon, and remove the display of stored credential values from the user administration.


Vendor Workaround

Until the service packs are installed, administrators can force a password change for accounts whose password was last set under a version before MEONA 2024.10; the new password is stored with Argon2.  Installations in which every password has been set or changed under MEONA 2024.10 or later are not affected. Details: Mesalvo Security Advisory MSA-2026-002.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Insufficient Password Hashing in Mesalvo MEONA Exposes Passwords
Type Values Removed Values Added
Description Cleartext Storage of Sensitive Information in Memory vulnerability in Mesalvo Meona Client Launcher Component, Mesalvo Meona Server Component. This issue affects Meona Client Launcher Component: through 19.06.2020 15:11:49; Meona Server Component: through 2025.04 5+323020. Use of a Password Hash With Insufficient Computational Effort in Mesalvo MEONA (MEONA Server and MEONA Client) for user accounts whose password was last set under a version before MEONA 2024.10. MEONA versions before 2024.10 protected stored passwords with SHA-1 (versions from October 2015) or stored them without protection (earlier versions). Since MEONA 2024.10 (June 2024) Argon2 is the default method and every password that is set or changed is stored with Argon2; passwords last set under an earlier version keep the earlier method until they are changed. An administrator could in addition select the storage method per account. A MEONA super administrator can read the stored value of such accounts in the user administration of the MEONA Client or export it through administrative database functions. Only accounts managed locally in MEONA are affected; accounts authenticated through the operating hospital's directory service (Active Directory / Entra ID) have no password stored in MEONA. In typical installations end users authenticate through the directory service and local accounts are limited to emergency and technical accounts. Exploitation requires super administrator permissions in MEONA (or direct access to the MEONA database) from within the operating hospital's network; MEONA is operated exclusively within closed hospital networks without exposure to the public Internet, and where a hospital permits remote access to that network at all, it is only through the hospital's own remote-access infrastructure (e.g. VPN) under the hospital's control. Installations in which every password has been set or changed under MEONA 2024.10 or later are not affected. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Server and MEONA Client in versions 2024.10, 2025.04 and 2026.03 (for accounts with passwords last set under earlier versions). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) remove the legacy storage methods, require every affected account to set a new Argon2-protected password at next logon, and no longer display stored credential values in the user administration. See Mesalvo Security Advisory MSA-2026-002.
Weaknesses CWE-916
References
Metrics cvssV3_1

{'score': 6, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N'}

cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
First Time appeared Mesalvo
Mesalvo meona Client Launcher Component
Mesalvo meona Server Component
Vendors & Products Mesalvo
Mesalvo meona Client Launcher Component
Mesalvo meona Server Component
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Cleartext Storage of Sensitive Information in Memory vulnerability in Mesalvo Meona Client Launcher Component, Mesalvo Meona Server Component. This issue affects Meona Client Launcher Component: through 19.06.2020 15:11:49; Meona Server Component: through 2025.04 5+323020.
Weaknesses CWE-316
References
Metrics cvssV3_1

{'score': 6, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ENISA
Published
Updated
Sep 25, 2026, 2:23 PM
Reserved
Jan 12, 2026, 6:14 AM
Status
Deferred
Published
May 20, 2026, 11:16 AM
Modified
Sep 25, 2026, 3:17 PM