{"id":"CVE-2026-116844","title":"Fclairamb ftpserverlib through 0.32.4 Cleartext FTPES Data Transfer via PROT P","summary":"Fclairamb ftpserverlib through 0.32.4 contains a cleartext transmission vulnerability because TransferOpen checks only the transferTLS flag set by PROT, not whether the prepared data connection uses TLS. When a client sends PROT P after …","severity":"medium","cvss":4.8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-319"],"vendor":"fclairamb","product":"ftpserverlib","affected":["ftpserverlib <= 0.32.4","syncplify_server <= 8.8.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-27T13:42:20.618045Z"},"published":"2026-10-27","updated":"2026-10-29","sourceUpdated":"2026-10-29T10:52:21.022Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116844","references":[{"url":"https://github.com/fclairamb/ftpserverlib/pull/685"},{"url":"https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/handle_misc.go#L29-L31"},{"url":"https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/client_handler.go#L720"},{"url":"https://www.vulncheck.com/advisories/fclairamb-ftpserverlib-through-0.32.4-cleartext-ftpes-data-transfer-via-prot-p","label":"VulnCheck Advisory: Fclairamb ftpserverlib through 0.32.4 Cleartext FTPES Data Transfer via PROT P"}],"tags":["cve.org"],"epss":0.0009,"epssPercentile":0.00403,"ingestedAt":"2026-10-27T16:11:59.444Z","slug":"CVE-2026-116844","body":"## Overview\n\nFclairamb ftpserverlib through 0.32.4 contains a cleartext transmission vulnerability because TransferOpen checks only the transferTLS flag set by PROT, not whether the prepared data connection uses TLS. When a client sends PROT P after PASV or PORT, file contents and directory listings cross the network unencrypted, even with mandatory encryption, letting on-path attackers read or modify them.\n\n## Affected\n\n- `ftpserverlib <= 0.32.4`\n- `syncplify_server <= 8.8.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":26.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}