{"id":"CVE-2026-86411","state":"PUBLISHED","title":"FTP connection reuse inherits client-certificate","description":"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 TLS handshake nor a new FTP login, so the server continues to authorize it\nunder the first handle's certificate identity.","publishedAt":"2026-10-20T20:02:03.431Z","updatedAt":"2026-10-29T18:42:03.095Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"CISA-ADP"},"assigner":"curl","products":["curl curl"],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.21.0","status":"affected","lessThanOrEqual":"8.21.0","versionType":"semver"}]}],"references":["https://curl.se/docs/CVE-2026-86411.json","https://curl.se/docs/CVE-2026-86411.html","https://hackerone.com/reports/3973190"],"weaknesses":["CWE-488"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/86xxx/CVE-2026-86411.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86411","state":"PUBLISHED","datePublished":"2026-10-20T20:02:03.431Z","dateUpdated":"2026-10-29T18:42:03.095Z","assignerShortName":"curl","assignerOrgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateReserved":"2026-09-07T12:11:48.560Z"},"containers":{"cna":{"title":"FTP connection reuse inherits client-certificate","descriptions":[{"lang":"en","value":"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 TLS handshake nor a new FTP login, so the server continues to authorize it\nunder the first handle's certificate identity."}],"affected":[{"vendor":"curl","product":"curl","defaultStatus":"unaffected","versions":[{"version":"8.21.0","status":"affected","lessThanOrEqual":"8.21.0","versionType":"semver"}]}],"references":[{"url":"https://curl.se/docs/CVE-2026-86411.json","name":"json"},{"url":"https://curl.se/docs/CVE-2026-86411.html","name":"www"},{"url":"https://hackerone.com/reports/3973190","name":"issue"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-488 Exposure of Data Element to Wrong Session"}]}],"providerMetadata":{"shortName":"curl","orgId":"2499f714-1537-4658-8207-48ae4bb9eae9","dateUpdated":"2026-10-20T20:02:03.431Z"},"credits":[{"lang":"en","value":"Stanislav Fort (Aisle Research)","type":"finder"},{"lang":"en","value":"Stefan Eissing","type":"remediation developer"}]},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://hackerone.com/reports/3973190","tags":["exploit"]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.1,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-10-29T18:41:51.847885Z","id":"CVE-2026-86411","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-488","type":"CWE","lang":"en","description":"CWE-488 Exposure of Data Element to Wrong Session"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-29T18:42:03.095Z"}}]}}}