{"id":"CVE-2026-19377","title":"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.","summary":"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.","severity":"medium","cvss":6,"cvssVector":"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","cwe":["CWE-295"],"vendor":"Cato Networks","product":"Cato Client for Windows","affected":["cato_client_for_windows < 6.12.6","cato_client_for_macos < 6.1.1","cato_client_for_linux < 5.8.1","cato_client_for_ios < 5.9","cato_client_for_android < 5.6.2"],"published":"2026-10-15","updated":"2026-10-15","sourceUpdated":"2026-10-15T07:17:59.143","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-19377","references":[{"url":"https://knowledge.catonetworks.com/docs/security-vulnerability-cve-2026-19377-that-impacts-cato-client-versions","label":"2505284f-8ffb-486c-bf60-e19c1097a90b"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-10-15T07:57:27.846Z","slug":"CVE-2026-19377","body":"## Overview\n\nImproper 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":33,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}