Cisco Unified Communications Manager (CUCM): Schwachstelle ermöglicht Manipulation von Dateien
WID-SEC-2026-1801 · first 05.06.2026 · updated 24.06.2026 · CVSS 8,6
What it is about
Der Cisco Unified Communications Manager (CUCM, ehemals CallManager) dient zur Gesprächsvermittlung in IP-Telefonie-Netzen. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Cisco Unified Communications Manager (CUCM) ausnutzen, um Dateien zu manipulieren und dadurch potenziell root Rechte zu erlangen.
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
- Dateien zu manipulieren
- dadurch potenziell root Rechte zu erlangen
Am I affected?
Affected according to the BSI:
- Cisco Unified Communications Manager (CUCM) <14SU6
- Cisco Unified Communications Manager (CUCM) <15SU5
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Cisco Unified Communications Manager (CUCM) 14SU6
- Cisco Unified Communications Manager (CUCM) 15SU5
Is the vulnerability already being exploited?
- CVE-2026-20230: exploited in the wild according to CISA, in the catalogue since 25.06.2026.
Information and sources
- Original BSI advisory (WID)
- Cisco Security Advisory cisco-sa-cucm-ssrf-cXPnHcW vom 2026-06-04 sec.cloudapps.cisco.com
- Bleeping Computer Artikel vom 2026-06-23 www.bleepingcomputer.com
CVE: CVE-2026-20230
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.