SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-1590

A vulnerability in the Transport Layer Security (TLS) certificate validation functionality of Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, remote attacker to perform insecure TLS…

HIGH 8.1EPSS 0.99%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.99%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A vulnerability in the Transport Layer Security (TLS) certificate validation functionality of Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, remote attacker to perform insecure TLS client authentication on an affected device. The vulnerability is due to insufficient TLS client certificate validations for certificates sent between the various components of an ACI fabric. An attacker who has possession of a certificate that is trusted by the Cisco Manufacturing CA and the corresponding private key could exploit this vulnerability by presenting a valid certificate while attempting to connect to the targeted device. An exploit could allow the attacker to gain full control of all other components within the ACI fabric of an affected device.

CVSS 3.0
8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.99% probability · 62th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-295
Affected
cisco/nx-os
Source
psirt@cisco.com
EPSS trend
0%3%5%27 October 2026: 0.99%27 October 202627 October 2026

EPSS 1.0% since 27 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.