CVE-2026-86411
FTP connection reuse inherits client-certificate
- State
- Published
- Severity
- 9.1 Critical
- Published
- Oct 20, 2026
- Updated
- Oct 29, 2026
- Reserved
- Sep 7, 2026
Description
An `ftp://` transfer configured with `CURLUSESSL_NONE` can reuse a pooled FTP control connection that a previous easy handle upgraded with `STARTTLS` and authenticated using a client certificate. The second handle performs neither a new TLS handshake nor a new FTP login, so the server continues to authorize it under the first handle's certificate identity.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | CISA-ADP |
Weaknesses
- CWE-488 Exposure of Data Element to Wrong Session
Affected Products
| Product | Versions |
|---|---|
curlcurl |
|
References
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