Cisco Secure Email Gateway: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen
WID-SEC-2026-3156 · first 03.09.2026 · updated 03.09.2026 · CVSS 5,9
What it is about
Cisco AsyncOS ist ein Betriebssystem für Cisco Appliances. Das Cisco Secure Email Gateway ist eine Sicherheitslösung zum Schutz der E-Mail Kommunikation. Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Cisco AsyncOS und Cisco Secure Email Gateway ausnutzen, um Sicherheitsvorkehrungen zu umgehen.
Under what conditions?
Over the network and without logging in. This is the most dangerous combination: attackers can scan reachable devices automatically.
What can happen in the worst case
An attacker could use the vulnerability to
- Sicherheitsvorkehrungen zu umgehen
Am I affected?
Affected according to the BSI:
- Cisco Secure Email Gateway
- Cisco AsyncOS <=16.5.0
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Cisco AsyncOS <=16.5.0
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)
- Cisco Security Advisory cisco-sa-esa-smime-disc-dzw4rEdY vom 2026-09-02 sec.cloudapps.cisco.com
CVE: CVE-2026-20354, CVE-2026-20355
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.