Vulnerability
curl/libcurl: wrong reuse of connections
libcurl can in some circumstances reuse the wrong connection when asked to do transfers using other protocols than HTTP and FTP. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to an error in the code, a transfer that was initiated by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. The existing logic only worked well enough for HTTP and FTP, while all other network protocols were silently, but erroneously, assumed to work like HTTP. Protocols that use connection oriented authentication need a new connection when new credentials are used. Affected protocols include: SCP, SFTP, POP3(S), IMAP(S), SMTP(S) and LDAP(S). Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API). (This problem is similar to a problem previously reported to NTLM HTTP connections, named [CVE-2014-0015](CVE-2014-0015.html))
No CVSS 3.x base score yet. Since April 2026 NVD only enriches priority CVEs (KEV, federal and critical software), so most CVEs are scored only if the assigning CNA included a score in the CVE record, or by GHSA for open-source packages. Last record update .
For interim severity, fall back on KEV / EXPLOIT signals and the EPSS percentile (lower panel). Re-check this CVE after one cron tick — the score lands automatically when the source publishes.
Mid-pack — moderate exploitation likelihood.
No VEX statements published for CVE-2014-0138. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.
No exploitation, limited impact or prevalence