CVE-2026-20056
Status: DeferredMedium (4)—
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.
Technical details traces, logs and code from the original report
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.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
- Base score: 4
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.16%
- Percentile among all scored CVEs: 5
- Score date: 10/6/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (2)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
CWEs
- CWE-494
References
Raw JSON (NVD)
Show
{
"id": "CVE-2026-20056",
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{
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"published": "2026-02-04T17:16:13.927",
"references": [
{
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-archive-bypass-Scx2e8zF",
"source": "psirt@cisco.com"
}
],
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"weaknesses": [
{
"type": "Secondary",
"source": "psirt@cisco.com",
"description": [
{
"lang": "en",
"value": "CWE-494"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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.\r\n\r\nThis 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. "
},
{
"lang": "es",
"value": "Una vulnerabilidad en la implementación del motor Dynamic Vectoring and Streaming (DVS) de Cisco AsyncOS Software para Cisco Secure Web Appliance podría permitir a un atacante remoto no autenticado eludir el escáner anti-malware, permitiendo la descarga de archivos comprimidos maliciosos.\n\nEsta vulnerabilidad se debe a un manejo inadecuado de ciertos archivos comprimidos. Un atacante podría explotar esta vulnerabilidad enviando un archivo comprimido manipulado, que debería ser bloqueado, a través de un dispositivo afectado. Un exploit exitoso podría permitir al atacante eludir el escáner anti-malware y descargar malware en una estación de trabajo de usuario final. El malware descargado no se ejecutará automáticamente a menos que el usuario final extraiga y ejecute el archivo malicioso."
}
],
"lastModified": "2026-06-17T10:16:59.583",
"sourceIdentifier": "psirt@cisco.com"
}