🔐 CVE Alert

CVE-2026-43965

UNKNOWN 0.0

Path Traversal in build/packages/packages.toml Allows Arbitrary Directory Deletion

CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th

Path traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content. 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. 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's system to be recursively deleted. This issue affects Gleam from 0.18.0-rc1 until 1.17.0.

CWE CWE-22
Vendor gleam
Product gleam
Published Jun 2, 2026
Last Updated Jun 2, 2026
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Affected Versions

Gleam / Gleam
0.18.0-rc1 < 1.17.0
Gleam / Gleam
0.18.0-rc1 < 1.17.0 ed7aec0484f10d60978b63788c8a6497590855ab < 690ca069817bee5f77a28fc3e360627c1da19291
Gleam / Gleam
v0.18.0-rc1-elixir < v1.17.0-elixir v0.18.0-rc1-erlang < v1.17.0-erlang v0.18.0-rc1-node < v1.17.0-node v0.18.0-rc1-node-slim < v1.17.0-node-slim v0.18.0-rc1-elixir-slim < v1.17.0-elixir-slim v0.18.0-rc1-erlang-slim < v1.17.0-erlang-slim v0.18.0-rc1-erlang-alpine < v1.17.0-erlang-alpine v0.18.0-rc1-elixir-alpine < v1.17.0-elixir-alpine v0.18.0-rc1-node-alpine < v1.17.0-node-alpine v0.18.0-rc1-scratch < v1.17.0-scratch

References

NVD ↗ CVE.org ↗ EPSS Data ↗
github.com: https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3 cna.erlef.org: https://cna.erlef.org/cves/CVE-2026-43965.html osv.dev: https://osv.dev/vulnerability/EEF-CVE-2026-43965 github.com: https://github.com/gleam-lang/gleam/commit/690ca069817bee5f77a28fc3e360627c1da19291

Credits

Aly (spect3r1) Abdelrahman Ahmed Aboelkasem (0x2face) Louis Pilfold Jonatan Männchen / EEF