{"id":"CVE-2026-86411","title":"FTP connection reuse inherits client-certificate","summary":"An `ftp://` transfer configured with `CURLUSESSL_NONE` can reuse a pooled FTP\ncontrol connection that a previous easy handle upgraded with `STARTTLS` and\nauthenticated using a client certificate. The second handle performs neither a\nnew …","severity":"none","cwe":["CWE-488"],"vendor":"curl","product":"curl","affected":["curl >= 8.21.0 <= 8.21.0"],"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T20:02:03.431Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-86411","references":[{"url":"https://curl.se/docs/CVE-2026-86411.json","label":"json"},{"url":"https://curl.se/docs/CVE-2026-86411.html","label":"www"},{"url":"https://hackerone.com/reports/3973190","label":"issue"}],"tags":["cve.org"],"ingestedAt":"2026-10-20T20:18:14.526Z","slug":"CVE-2026-86411","body":"## Overview\n\nAn `ftp://` transfer configured with `CURLUSESSL_NONE` can reuse a pooled FTP\ncontrol connection that a previous easy handle upgraded with `STARTTLS` and\nauthenticated using a client certificate. The second handle performs neither a\nnew TLS handshake nor a new FTP login, so the server continues to authorize it\nunder the first handle's certificate identity.\n\n## Affected\n\n- `curl >= 8.21.0 <= 8.21.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}