Vulnerability in Fclairamb Ftpserverlib
CVE-2026-116844
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 PASV or PORT, file contents and directory listings cross the network unencrypted, even with mandatory encryption, letting on-path attackers read or modify them.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/fclairamb/ftpserverlib/blob/v0.32.4/client_handler.go (technical-description)
- github.com/fclairamb/ftpserverlib/blob/v0.32.4/handle_misc.go (technical-description)
- github.com/fclairamb/ftpserverlib/pull/685 (issue-tracking, patch)
- www.vulncheck.com/advisories/fclairamb-ftpserverlib-through-0.32.4-cleartext-ft… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116844?
- CVE-2026-116844 is a medium-severity vulnerability in Fclairamb Ftpserverlib, classified under Cleartext Transmission of Sensitive Information. CVSS score: 4.8/10. Published 2026-10-27.
- How severe is CVE-2026-116844?
- Medium severity. CVSS v3 base score is 4.8 out of 10.