When libcurl uses libssh2 with a hashed known_hosts file, an unrelated initial entry can cause host key validation to report a key mismatch as a missing key to the CURLOPT_SSH_KEYFUNCTION callback.
known_hosts
CURLOPT_SSH_KEYFUNCTION
"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-87865.json"