Package metadata is the structured information bundled with a software dependency package, such as its name, version, files to install, scripts to run, and paths to create or modify. Installers and package managers use this data to decide how to place files, register executables, and prepare a project for use. In other words, metadata is not just descriptive text; it can directly drive install-time behavior.
In cyber security, package metadata matters because it sits on the trust boundary between a repository and the host system. If an attacker can tamper with metadata, they may influence where files are written, whether helper binaries are exposed, or which commands are triggered during installation. That can lead to path traversal, file overwrite, permission changes, or execution of unwanted code. Defenders reduce this risk by validating package contents, restricting installer privileges, checking that paths stay inside the intended directory, and reviewing dependency provenance. Secure package handling treats metadata as untrusted input, not as harmless bookkeeping.