CVE-2026-86411

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.

EPSS

0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-25)

Published

2026-10-20

Modified

2026-10-22

Record from

the NVD, synced 2026-10-23

References

• https://curl.se/docs/CVE-2026-86411.html
• https://curl.se/docs/CVE-2026-86411.json
• https://hackerone.com/reports/3973190

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