Fclairamb ftpserverlib through 0.32.4 contains a cleartext transmission vulnerability because TransferOpen checks only
Affects ftpserverlibSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium.
Data as of 27 Oct 2026, 04:16 UTC
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubfclairamb/ftpserverlibpkg:github/fclairamb/ftpserverlibOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should verify if newer versions beyond 0.32.4 address this issue or apply additional network-level protections such as enforcing TLS on data connections independently of the PROT flag. Monitor vendor advisories for updates. Since this is not a cloud service, remediation depends on updating or configuring the affected software.
Description
Fclairamb ftpserverlib versions through 0.32.4 have a vulnerability where file contents and directory listings can be transmitted in cleartext despite mandatory encryption settings. This occurs because the TransferOpen function only checks the transferTLS flag set by the PROT command, not whether the actual data connection uses TLS. An attacker on the network path can read or modify transferred data when a client sends PROT P after PASV or PORT commands.
References
- nvd.nist.gov/vuln/detail/CVE-2026-116844 (opens in a new tab)
- github.com/fclairamb/ftpserverlib/pull/685 (opens in a new tab)
- github.com/fclairamb/ftpserverlib/blob/v0.32.4/client_handler.go (opens in a new tab)
- github.com/fclairamb/ftpserverlib/blob/v0.32.4/handle_misc.go (opens in a new tab)
- vulncheck.com/advisories/fclairamb-ftpserverlib-through-0.32.4-cleartext-ftpes-data-transfer-via-prot-p (opens in a new tab)