The Connection::unidir_receive function in the plugin-support crate (age-core/src/plugin.rs:229-279) appends every stanza to in-memory vectors with no upper bound. A misbehaving or malicious peer can stream arbitrary data and exhaust memory, leading to denial-of-service attacks.

Recommendation:

Impose hard per-phase caps (e.g., 1,024 stanzas or 8 MiB total) and abort on excess. The implementation should validate vector sizes before appending and return appropriate errors when limits are exceeded, preventing memory exhaustion while maintaining protocol compatibility.