Improper certificate validation in Cato Client tunnel handshake
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.
CVE-2026-19377
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-19377
Cato Client for Windows
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Cato Client for macOS
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Cato Client for Linux
Source reference: /containers/cna/affected/2/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Cato Client for iOS
Source reference: /containers/cna/affected/3/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Cato Client for Android
Source reference: /containers/cna/affected/4/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Cato Networks",
"product": "Cato Client for Windows",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "6.12.6",
"versionType": "custom"
}
],
"platforms": [
"Windows"
],
"defaultStatus": "unaffected"
},
{
"vendor": "Cato Networks",
"product": "Cato Client for macOS",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "6.1.1",
"versionType": "custom"
}
],
"platforms": [
"macOS"
],
"defaultStatus": "unaffected"
},
{
"vendor": "Cato Networks",
"product": "Cato Client for Linux",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "5.8.1",
"versionType": "custom"
}
],
"platforms": [
"Linux"
],
"defaultStatus": "unaffected"
},
{
"vendor": "Cato Networks",
"product": "Cato Client for iOS",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "5.9",
"versionType": "custom"
}
],
"platforms": [
"iOS"
],
"defaultStatus": "unaffected"
},
{
"vendor": "Cato Networks",
"product": "Cato Client for Android",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "5.6.2",
"versionType": "custom"
}
],
"platforms": [
"Android"
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-19377
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #28818 · Revision 1
- Added to Heist Feed
- Publisher date