Gleam vulnerabilities

A vulnerability in Gleam allows a man-in-the-middle attacker to substitute forged Hex package contents during dependency resolution due to insufficient verification of data authenticity. The second request to the unsigned Hex API is used instead of verified repository metadata.

Path traversal vulnerability in Gleam's dependency management (versions 0.18.0-rc1 through 1.17.0) allows arbitrary directory deletion via malicious build/packages/packages.toml content. Package keys are used without validation to construct paths, allowing ../ sequences to escape the intended directory.

A symlink following vulnerability in Gleam's Hex package export allows files outside the project root to be embedded in the generated package tarball. File collection helpers use follow_links(true) when walking publishable directories, and paths are added to the archive without verifying that the resolved target remains within the project root.

Path traversal vulnerability in Gleam's custom documentation pages handling (versions 1.16.0 through 1.17.0) allows arbitrary file read and write outside the intended documentation output directory. The documentation.pages[].path and .source fields are used without sufficient validation.

A path validation vulnerability in the Gleam compiler's handling of git dependencies allows arbitrary file system modification during dependency download. Dependency names from gleam.toml and manifest.toml are used in filesystem paths without sufficient validation, enabling path traversal (e.g., ../) to access files outside the intended dependency directory. A malicious dependency can delete or overwrite arbitrary directories, potentially leading to data loss or code execution.