SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-3363

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.

HIGH 8.6EPSS 1.82%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.82%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 an unexpected reboot of the switch, leading to a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

CVSS 3.1
8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
1.82% probability · 79th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20
Affected
cisco/sg250x-24 firmware · cisco/sg250x-24p firmware · cisco/sg250x-48 firmware · cisco/sg250x-48p firmware · cisco/sg250-08 firmware · cisco/sg250-08hp firmware · cisco/sg250-10p firmware · cisco/sg250-18 firmware · cisco/sg250-26 firmware · cisco/sg250-26hp firmware · cisco/sg250-26p firmware · cisco/sg250-50 firmware · cisco/sg250-50hp firmware · cisco/sg250-50p firmware · cisco/sf250-24 firmware · cisco/sf250-24p firmware · cisco/sf250-48 firmware · cisco/sf250-48hp firmware · cisco/sg350-10 firmware · cisco/sg350-10p firmware · +40 more
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 1.82%26 October 202626 October 2026

EPSS 1.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.