Encrypting a CMS message to an EC certificate with a group order of 1 can cause the `CMS encrypt()` or `CMS encrypt ex()` functions to loop indefinitely. This occurs because the key generation routine retries without limit while waiting for a nonzero private scalar, which cannot be produced if the group order is 1. An attacker who can provide a recipient certificate with controlled EC parameters to an application performing CMS encryption can trigger this behavior, leading to a Denial of Service by consuming a CPU core until the process is interrupted. The OpenSSL TLS and QUIC implementations are not affected, and FIPS modules in versions 3.0, 3.5, 4.0, and 4.1 are not impacted as they reject arbitrary explicit EC domain parameters.