Vulnerability in Cisco Secure Web Appliance

CVE-2026-20056

A vulnerability in the Dynamic Vectoring and Streaming (DVS) Engine implementation of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to bypass the anti-malware scanner, allowing malicious archive files to be downloaded. This vulnerability is due to improper handling of certain archive files. An attacker could exploit this vulnerability by sending a crafted archive file, which should be blocked, through an affected device. A successful exploit could allow the attacker to bypass the anti-malware scanner and download malware onto an end user workstation. The downloaded malware will not automatically execute unless the end user extracts and launches the malicious file. 

EPSS: 0.001 (4.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20056?
CVE-2026-20056 is a medium-severity vulnerability in Cisco Secure Web Appliance, classified under Download of Code Without Integrity Check. CVSS score: 4.0/10. Published 2026-02-04.
How severe is CVE-2026-20056?
Medium severity. CVSS v3 base score is 4.0 out of 10.