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Vulnerability record · CVE-2020-3496 · published 26 August 2020

CVE-2020-3496: Cisco sg200-50 firmware improper input validation vulnerability

Cisco · Sg200 50 Firmware

A vulnerability in the IPv6 packet processing engine of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet through an affected device. A successful exploit could allow the attacker to cause the switch management CLI to stop responding, resulting in a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

5.3 CVSS 3.1 Medium EPSS 1.7% · top 23.1% CWE-20 · Improper input validation
5.3CVSS 3.1 base score, v2 5.0
1.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
114Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A vulnerability in the IPv6 packet processing engine of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet through an affected device. A successful exploit could allow the attacker to cause the switch management CLI to stop responding, resulting in a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

114 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sbss-ipv6-dos-tsgqbffW Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sbss-ipv6-dos-tsgqbffW Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2020-3496), CISA KEV, FIRST EPSS (scores of 2026-10-04). This page is refreshed as NVD updates the record.