CVE-2026-19377: Improper certificate validation in Cato Client tunnel handshake
Published Oct 15, 2026
·Updated
Improper certificate validation in the tunnel handshake in Cato Client allows a man-in-the-middle attacker to impersonate a Cato Point of Presence (PoP) server and intercept or modify tunnel traffic.
Affected Software
1 affected component
Cato Cato Client
Event History
Oct 15, 2026
CVE Published
via MITRE·07:02 AM
Data Sourced
via MITRE·07:02 AM
DescriptionWeakness
Frequently Asked Questions
1
What access does an attacker need to exploit this issue?
An attacker must be able to perform a man-in-the-middle attack on the Cato Client tunnel handshake, allowing them to impersonate a Cato Point of Presence server.
2
What could an attacker do if exploitation succeeds?
The attacker could intercept or modify traffic carried through the affected tunnel.