CVE-2026-19377 Improper certificate validation in Cato Client tunnel handshake
A man-in-the-middle attacker can bypass certificate validation to impersonate a server and intercept or modify tunnel traffic.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-19377?
CVE-2026-19377 is a medium-severity vulnerability in Cato Client for Android, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-295
Which versions are affected by CVE-2026-19377?
How do I fix CVE-2026-19377?
No fix has been published for CVE-2026-19377 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-19377 being exploited?
There is no known exploitation of CVE-2026-19377 in the wild and no public exploit code.
Sources
Also known as GHSA-v76q-8hm2-wrx6.