CVE-2026-32146

Summary

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 1.15.4.

Affected Software

VendorProductVersion RangeStatus
GleamGleam1.9.0-rc1 < *affected
GleamGleam1.9.0-rc1 < *affected
GleamGleama4fde22445ab8e5cc79c2ff48971616cb570702c < *affected
GleamGleamv1.9.0-rc1-elixir < v1.15.4-elixiraffected
GleamGleamv1.9.0-rc1-erlang < v1.15.4-erlangaffected
GleamGleamv1.9.0-rc1-node < v1.15.4-nodeaffected
GleamGleamv1.9.0-rc1-node-slim < v1.15.4-node-slimaffected
GleamGleamv1.9.0-rc1-elixir-slim < v1.15.4-elixir-slimaffected
GleamGleamv1.9.0-rc1-erlang-slim < v1.15.4-erlang-slimaffected
GleamGleamv1.9.0-rc1-erlang-alpine < v1.15.4-erlang-alpineaffected
GleamGleamv1.9.0-rc1-elixir-alpine < v1.15.4-elixir-alpineaffected
GleamGleamv1.9.0-rc1-node-alpine < v1.15.4-node-alpineaffected
GleamGleamv1.9.0-rc1-scratch < v1.15.4-scratchaffected

Weaknesses

  • CWE-22: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Workarounds

  • Avoid using untrusted git dependencies, especially without pinning to a specific commit SHA
  • Review dependency trees carefully, including transitive git dependencies
  • Run dependency resolution commands in a restricted or isolated environment (e.g. containers)

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

gleam: Gleam compiler: Arbitrary file system modification and potential code execution via improper path validation in git dependency handling.

Additional References

References