CVE-2026-19377

Medium

Description

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.

SeverityMedium

CVSS6.0

Exploit probability—

ProductCato Client for Windows

PublishedOct 15, 2026

First seenOct 15, 2026

Weakness typeCWE-295CWE-295

How to fix

Update

Cato Networks Cato Client for Windows6.12.6 or later
Cato Networks Cato Client for macOS6.1.1 or later
Cato Networks Cato Client for Linux5.8.1 or later
Cato Networks Cato Client for iOS5.9 or later
Cato Networks Cato Client for Android5.6.2 or later

Vendor advisories

knowledge.catonetworks.com/docs/security-vulnerability-cve-2026-19377-that-impacts-cato-client-versions

Affected products

Product	Affected versions	Fixed in
Cato Networks Cato Client for Windows	v < 6.12.6	6.12.6
Cato Networks Cato Client for macOS	v < 6.1.1	6.1.1
Cato Networks Cato Client for Linux	v < 5.8.1	5.8.1
Cato Networks Cato Client for iOS	v < 5.9	5.9
Cato Networks Cato Client for Android	v < 5.6.2	5.6.2

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