Synology MailPlus Server: Mehrere Schwachstellen
WID-SEC-2026-2140 · first 01.07.2026 · updated 01.07.2026 · CVSS 10,0
What it is about
Synology MailPlus Server ist eine E-Mail-Lösung, die ein Synology NAS in einen privaten Mailserver verwandelt. Ein Angreifer kann mehrere Schwachstellen in Synology MailPlus Server ausnutzen, um Dateien zu manipulieren, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand auszulösen.
Under what conditions?
The BSI does not name any particular preconditions. Exploitable remotely according to the BSI.
What can happen in the worst case
An attacker could use the vulnerability to
- Dateien zu manipulieren
- Sicherheitsmaßnahmen zu umgehen
- vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand auszulösen
Am I affected?
Affected according to the BSI:
- Synology MailPlus Server DSM 7.3 <4.0.1-31663
- Synology MailPlus Server DSM 7.2.2 <4.0.1-21663
- Synology MailPlus Server DSM 7.2.1 <4.0.1-21663
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Synology MailPlus Server DSM 7.3 4.0.1-31663
- Synology MailPlus Server DSM 7.2.2 4.0.1-21663
- Synology MailPlus Server DSM 7.2.1 4.0.1-21663
Is the vulnerability already being exploited?
None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.
Information and sources
- Original BSI advisory (WID)
- Synology Security Advisory vom 2026-06-30 www.synology.com
CVE: CVE-2025-15660, CVE-2026-13135, CVE-2026-13136
Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.