Vulnerability · Published Oct 15, 2026 · Assigned by Cato
CVE-2026-19377Improper certificate validation in Cato Client tunnel handshake
Medium 6.0
In plain English
A medium-severity improper certificate validation in Cato Client for Android from Cato Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 0% of all known vulnerabilities).
Severity (CVSS 4.0)6.0Medium
Exploit odds (30 days)<0.1%top 99.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cato Networks | Cato Client for Windows | 0 – before 6.12.6 |
| Cato Networks | Cato Client for macOS | 0 – before 6.1.1 |
| Cato Networks | Cato Client for Linux | 0 – before 5.8.1 |
| Cato Networks | Cato Client for iOS | 0 – before 5.9 |
| Cato Networks | Cato Client for Android | 0 – before 5.6.2 |
Weakness: CWE-295 · Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
References
- Cato Networks Security Advisory vendor-advisory