curl: curl: Insecure connection establishment due to TLS configuration mismatch

A flaw was found in curl. When a new data transfer attempts to upgrade its connection using STARTTLS, it may incorrectly reuse an existing live connection. This reuse can occur even if the Transport Layer Security TLS configuration of the new transfer does not match the existing connection,...

CURL-CVE-2026-8286 wrong STARTTLS connection reuse

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not...