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Fencer Intel
medium 4.0

CVE-2026-20056 json

Cisco Secure Web Appliance TBD Bypass Vulnerability

published 9mo ago modified 4mo ago also EUVD-2026-5425

cvss
4.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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. 

Is CVE-2026-20056 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
9mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 4.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N

Affected products

  • Cisco Cisco Secure Web Appliance

Classification

Weakness
  • CWE-494 Download of Code Without Integrity Check

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.