CVE-2026-86411— FTP connection reuse inherits client-certificate
Quick assessment
Affected
curl curl
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
配置为 的 传输可以复用之前某个简单句柄（easy handle）通过 升级并使用客户端证书进行身份验证后建立的 FTP 控制连接池中的连接。由于第二个句柄既未执行新的 TLS 握手，也未执行新的 FTP 登录，服务器将继续依据第一个句柄的证书身份对其进行授权。
Possible ATT&CK Techniques 2 AI
T1550.004 · Web Session Cookie T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-86411
Vulnerability Information
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Vulnerability Title
FTP connection reuse inherits client-certificate
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-86411
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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Vendor Pages for CVE-2026-86411 (2)
Other References for CVE-2026-86411 (1)
Same Patch Batch · curl · 2026-10-20 · 23 CVEs total
| CVE-2026-92389 | TFTP direction confusion | |
| CVE-2026-107928 | info leak uploading over WebSockets with GnuTLS | |
| CVE-2026-107929 | local interface connection reuse mixup | |
| CVE-2026-94266 | password leak in CURLINFO_EFFECTIVE_URL | |
| CVE-2026-94265 | Authorization: Negotiate sent to foreign origin | |
| CVE-2026-86415 | auto client cert connection reuse mixup | |
| CVE-2026-86414 | leaking host credentials to HTTP proxy | |
| CVE-2026-92390 | -J no-clobber guarantee bypassed with 103 early hints | |
| CVE-2026-92387 | never-ending loop via server response omission | |
| CVE-2026-92388 | FTP wildcard write callback mixup | |
| CVE-2026-92386 | server-set cookie aborts cookie jar load | |
| CVE-2026-86409 | stale SigV4 headers sent unintended | |
| CVE-2026-92391 | curl_mime_free stack overflow by recursion | |
| CVE-2026-87865 | knownhost callback mismatches key as missing | |
| CVE-2026-87864 | IMAP APPEND plus CRLF conversion command injection | |
| CVE-2026-87863 | HSTS response erases persisted entries | |
| CVE-2026-87866 | wolfSSL public-key pinning bypass | |
| CVE-2026-87861 | cross-origin reuse of a Negotiate connection | |
| CVE-2026-87862 | HSTS cache import drops longer-lived child | |
| CVE-2026-86412 | server-set cookie erases cookie jar |
Showing top 20 of 23 CVEs. View all on vendor page → →