Medium severity · published Oct 27, 2026
CVE-2026-116844
Fclairamb ftpserverlib through 0.32.4 Cleartext FTPES Data Transfer via PROT P
New
4.8
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 0% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FT
ftpserverlib · fclairamb
through 0.32.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-116844
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-116844
github.com
https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/client_handler.go#L720
github.com
https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/handle_misc.go#L29-L31
github.com
https://github.com/fclairamb/ftpserverlib/pull/685
www.vulncheck.com
https://www.vulncheck.com/advisories/fclairamb-ftpserverlib-through-0.32.4-cleartext-ftpes-data-transfer-via-prot-p