Description
Improper 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 incorporated into filesystem paths without sufficient validation or confinement to the intended dependency directory, allowing attacker-controlled paths (via relative traversal such as ../ or absolute paths) to target filesystem locations outside that directory. When resolving git dependencies (e.g. via gleam deps download), the computed path is used for filesystem operations including directory deletion and creation. This vulnerability occurs during the dependency resolution and download phase, which is generally expected to be limited to fetching and preparing dependencies within a confined directory. A malicious direct or transitive git dependency can exploit this issue to delete and overwrite arbitrary directories outside the intended dependency directory, including attacker-chosen absolute paths, potentially causing data loss. In some environments, this may be further leveraged to achieve code execution, for example by overwriting git hooks or shell configuration files. This issue affects Gleam from 1.9.0-rc1 until 1.15.3 and 1.16.0-rc1.
Problem types
CWE-22 Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’)
Product status
1.9.0-rc1 (semver) before *
1.9.0-rc1 (semver) before *
a4fde22445ab8e5cc79c2ff48971616cb570702c (git) before *
Credits
John Downey
Louis Pilfold
Jonatan Männchen / EEF
References
github.com/…/gleam/security/advisories/GHSA-vq5j-55vx-wq8j
cna.erlef.org/cves/CVE-2026-32146.html
osv.dev/vulnerability/EEF-CVE-2026-32146
github.com/…ommit/1aa5d8e594b0aa240bb213fce6ee19c65e6d5bcf
github.com/…ommit/55bb36e6d7febfbbc48c4d001e0ae13eb0312d78
