{"id":"CVE-2026-19377","revision":"11396c78a0874bc184e86ac814c4b5b9","records":[{"revision":"11396c78a0874bc184e86ac814c4b5b9","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-19377","aliases":[],"title":"Improper certificate validation in Cato Client tunnel handshake","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.","state":0,"publishedAt":"2026-10-15T07:02:10.937+00:00","modifiedAt":"2026-10-15T14:22:58.368+00:00","affected":[{"ecosystem":"Vendor product","name":"Cato Client for Windows","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Cato Networks\",\n                    \"product\": \"Cato Client for Windows\",\n                    \"platforms\": [\n                        \"Windows\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.12.6\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"},{"ecosystem":"Vendor product","name":"Cato Client for macOS","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Cato Networks\",\n                    \"product\": \"Cato Client for macOS\",\n                    \"platforms\": [\n                        \"macOS\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.1.1\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"},{"ecosystem":"Vendor product","name":"Cato Client for Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Cato Networks\",\n                    \"product\": \"Cato Client for Linux\",\n                    \"platforms\": [\n                        \"Linux\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.8.1\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"},{"ecosystem":"Vendor product","name":"Cato Client for iOS","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Cato Networks\",\n                    \"product\": \"Cato Client for iOS\",\n                    \"platforms\": [\n                        \"iOS\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.9\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"},{"ecosystem":"Vendor product","name":"Cato Client for Android","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Cato Networks\",\n                    \"product\": \"Cato Client for Android\",\n                    \"platforms\": [\n                        \"Android\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.6.2\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 4.0","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","score":6,"severity":"MEDIUM"}],"references":["https://knowledge.catonetworks.com/docs/security-vulnerability-cve-2026-19377-that-impacts-cato-client-versions"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-19377","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-19377","identifiers":["CVE-2026-19377"]},"retained":false,"historicalAffected":[]}],"coverage":[]}