Cisco Secure Web Appliance: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen
WID-SEC-2026-0311 · first 05.02.2026 · updated 05.02.2026 · CVSS 4,0
What it is about
Cisco Secure Web Appliance (ehem. Cisco Web Security) bietet einen on-premise Web Proxy mit Schutz vor vielen Bedrohungen. Cisco AsyncOS ist ein Betriebssystem für Cisco Appliances. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Cisco Secure Web Appliance und Cisco AsyncOS 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 Web Appliance
- Cisco AsyncOS <15.2.5-011
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Cisco AsyncOS 15.2.5-011
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 Advisories vom 2026-02-04 sec.cloudapps.cisco.com
CVE: CVE-2026-20056
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.