CVE-2026-43965
Severity CVSS v4.0:
MEDIUM
Type:
CWE-22
Path Traversal
Publication date:
02/06/2026
Last modified:
02/06/2026
Description
Path traversal vulnerability in Gleam&#39;s dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content.<br />
<br />
Package keys read from build/packages/packages.toml by LocalPackages::read_from_disc are passed without validation to paths.build_packages_package(), which constructs a filesystem path by joining the project build directory with the attacker-controlled key. The resulting path is then passed to fs::delete_directory (which calls remove_dir_all). No check is performed to ensure the path remains within the intended build/packages/ directory. Both absolute paths and relative traversal sequences (e.g. ../) are accepted as package keys, allowing deletion of arbitrary directories.<br />
<br />
An attacker who can cause a victim to run gleam deps download on a project containing a malicious build/packages/packages.toml (e.g. by committing the normally-gitignored file to a repository) can cause arbitrary directories on the victim&#39;s system to be recursively deleted.<br />
<br />
This issue affects Gleam from 0.18.0-rc1 until 1.17.0.
Impact
Base Score 4.0
5.60
Severity 4.0
MEDIUM
References to Advisories, Solutions, and Tools
- https://cna.erlef.org/cves/CVE-2026-43965.html
- https://github.com/gleam-lang/gleam/commit/690ca069817bee5f77a28fc3e360627c1da19291
- https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3
- https://osv.dev/vulnerability/EEF-CVE-2026-43965
- https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3