CVE-2026-25602

Internal email spoofing via unchecked recipient field

Published May 20, 2026 · Updated May 20, 2026

Email spoofing in Mesalvo Meona client and server components allows local users to send messages to arbitrary email addresses. The launcher sends serialized Hessian feedback objects over HTTP, and the server accepts a modified recipient field without checking it against the hardcoded address. Client Launcher 19.06.2020 15:11:49 and earlier and Server 2025.04 5+323020 and earlier are affected; low-privilege application access is required.

CVSS severity4.4
Medium
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Email spoofing in Mesalvo Meona client and server components allows local users to send messages to arbitrary email addresses. The launcher sends serialized Hessian feedback objects over HTTP, and the server accepts a modified recipient field without checking it against the hardcoded address. Client Launcher 19.06.2020 15:11:49 and earlier and Server 2025.04 5+323020 and earlier are affected; low-privilege application access is required.

The record

CVE
CVE-2026-25602
Published
May 20, 2026
Updated
May 20, 2026
Vendor
Mesalvo
Product
Meona Client Launcher Component
Classifications
CWE-345, T1656
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=19.06.2020 15:11:49

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Mesalvo · Meona Client Launcher Componentversion=0 <=19.06.2020 15:11:49
Mesalvo · Meona Server Componentversion=0 <=2025.04 5+323020

Published CVSS scores

4.4ENISACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1656Impersonation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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