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Full vulnerability report · 2026
CVE-2026-25602High confidence

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server)

Mesalvo · Meona Server

2.3LowCVSS 3.1
Recommended action
Scheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityLowOperational priority:Low, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.09% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Mesalvo Meona Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-31094

No EUVD known-exploited evidence

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server). The MEONA Client transmits the recipient address of a feedback report to the MEONA Server, and the server sends the report to the transmitted address instead of the address configured on the server. The feedback function is available only in the MEONA administration area, which requires one of the administrative roles ADMINISTRATOR, SUPERADMINISTRATOR or TYPIST (catalogue editing), or the PHARMACIST role holding the PHARMACY_ADMINISTRATOR right, assigned explicitly by the operating hospital's administrators. Such a user who modifies the client request can cause the MEONA Server to send a message with content of the user's choosing, from the sender address configured on the server, to a recipient of the user's choosing, within the limits permitted by the operator's mail relay. The message can be used for social engineering because it appears to originate from an internal hospital system. Exploitation requires a MEONA account with one of the administrative roles named above and access to the operating hospital's internal 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. The message contains only the recipient, subject and text entered by the user; no data of other users or patients is disclosed. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 (before 2025.04.24) and 2026.03 (before 2026.03.02). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the server. Operators can restrict at their mail relay which recipients the MEONA sender address may reach.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
2.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server). The MEONA Client transmits the recipient address of a feedback report to the MEONA Server, and the server sends the report to the transmitted address instead of the address configured on the server. The feedback function is available only in the MEONA administration area, which requires one of the administrative roles ADMINISTRATOR, SUPERADMINISTRATOR or TYPIST (catalogue editing), or the PHARMACIST role holding the PHARMACY_ADMINISTRATOR right, assigned explicitly by the operating hospital's administrators. Such a user who modifies the client request can cause the MEONA Server to send a message with content of the user's choosing, from the sender address configured on the server, to a recipient of the user's choosing, within the limits permitted by the operator's mail relay. The message can be used for social engineering because it appears to originate from an internal hospital system. Exploitation requires a MEONA account with one of the administrative roles named above and access to the operating hospital's internal 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. The message contains only the recipient, subject and text entered by the user; no data of other users or patients is disclosed. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 (before 2025.04.24) and 2026.03 (before 2026.03.02). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the server. Operators can restrict at their mail relay which recipients the MEONA sender address may reach.

What

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server). The MEONA Client transmits the recipient address of a feedback report to the MEONA Server, and the server sends the report to the transmitted address instead of the address configured on the server. The feedback function is available only in the MEONA administration area, which requires one of the administrative roles ADMINISTRATOR, SUPERADMINISTRATOR or TYPIST (catalogue editing), or the PHARMACIST role holding the PHARMACY_ADMINISTRATOR right, assigned explicitly by the operating hospital's administrators. Such a user who modifies the client request can cause the MEONA Server to send a message with content of the user's choosing, from the sender address configured on the server, to a recipient of the user's choosing, within the limits permitted by the operator's mail relay. The message can be used for social engineering because it appears to originate from an internal hospital system. Exploitation requires a MEONA account with one of the administrative roles named above and access to the operating hospital's internal 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. The message contains only the recipient, subject and text entered by the user; no data of other users or patients is disclosed. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 (before 2025.04.24) and 2026.03 (before 2026.03.02). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the server. Operators can restrict at their mail relay which recipients the MEONA sender address may reach.

Why

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

How

An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server). The MEONA Client transmits the recipient address of a feedback report to the MEONA Server, and the server sends the report to the transmitted address instead of the address configured on the server. The feedback function is available only in the MEONA administration area, which requires one of the administrative roles ADMINISTRATOR, SUPERADMINISTRATOR or TYPIST (catalogue editing), or the PHARMACIST role holding the PHARMACY_ADMINISTRATOR right, assigned explicitly by the operating hospital's administrators. Such a user who modifies the client request can cause the MEONA Server to send a message with content of the user's choosing, from the sender address configured on the server, to a recipient of the user's choosing, within the limits permitted by the operator's mail relay. The message can be used for social engineering because it appears to originate from an internal hospital system. Exploitation requires a MEONA account with one of the administrative roles named above and access to the operating hospital's internal 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. The message contains only the recipient, subject and text entered by the user; no data of other users or patients is disclosed. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 (before 2025.04.24) and 2026.03 (before 2026.03.02). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the server. Operators can restrict at their mail relay which recipients the MEONA sender address may reach.

Why

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

How

An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Insufficient Verification of Data Authenticity → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-345 ↗

CWE-345: Insufficient Verification of Data Authenticity. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
CWE-345
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-31094Official EUVD mapping

Insufficient Verification of Data Authenticity in the feedback function of Mesalvo MEONA (MEONA Client and MEONA Server). The MEONA Client transmits the recipient address of a feedback report to the MEONA Server, and the server sends the report to the transmitted address instead of the address configured on the server. The feedback function is available only in the MEONA administration area, which requires one of the administrative roles ADMINISTRATOR, SUPERADMINISTRATOR or TYPIST (catalogue editing), or the PHARMACIST role holding the PHARMACY_ADMINISTRATOR right, assigned explicitly by the operating hospital's administrators. Such a user who modifies the client request can cause the MEONA Server to send a message with content of the user's choosing, from the sender address configured on the server, to a recipient of the user's choosing, within the limits permitted by the operator's mail relay. The message can be used for social engineering because it appears to originate from an internal hospital system. Exploitation requires a MEONA account with one of the administrative roles named above and access to the operating hospital's internal 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. The message contains only the recipient, subject and text entered by the user; no data of other users or patients is disclosed. Mesalvo is not aware of any exploitation outside the reported security test. This issue affects MEONA Client and MEONA Server in versions 2024.10, 2025.04 (before 2025.04.24) and 2026.03 (before 2026.03.02). MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the server. Operators can restrict at their mail relay which recipients the MEONA sender address may reach.

Official EUVD record ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the MEONA Server and ignore any client-supplied recipient.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 20 May 2026 · Last source change 25 Sept 2026, 14:39 UTC · CWE-345 · Insufficient Verification of Data Authenticity

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-31094
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: mesalvo.com/msa-2026-005.pdf.
    Before
    remediation: mesalvo.com/msa-2026-005.pdf · vendor advisory: mesalvo.com/msa-2026-005.pdf
    After
    remediation: mesalvo.com/msa-2026-005.pdf
    CNA ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: added remediation: mesalvo.com/msa-2026-005.pdf; added vendor advisory: mesalvo.com/msa-2026-005.pdf.
    Before
    no authoritative guidance recorded
    After
    remediation: mesalvo.com/msa-2026-005.pdf · vendor advisory: mesalvo.com/msa-2026-005.pdf
    mesalvo.com ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    ≤ 19.06.2020 15:11:49; ≤ 2025.04 5+323020 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Meona Server: 2024.10, 2025.04 < 2025.04.24, 2026.03 < 2026.03.02; Meona Client: 2024.10, 2025.04 < 2025.04.24, 2026.03 < 2026.03.02 · Fixed: MEONA 2025.04.24 and 2026.03.02 (planned Q4 2026) enforce the configured recipient address on the MEONA Server and ignore any client-supplied recipient.
    CNA ↗
  4. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    mesalvo.com ↗
  5. SeveritySeverity changed from Medium to Low.
    Before
    Medium
    After
    Low
    CNA ↗
  6. CVSS scoreCVSS score changed from 4.4 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N) to 2.3 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N).
    Before
    4.4 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
    After
    2.3 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N)
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-31094↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-25602 · cve.blacktree.nl