CVE-2026-43965

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.

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.

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.

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.

Summary

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.

These are all security issues fixed in the gleam-1.17.0-1.1 package on the GA media of openSUSE Tumbleweed.

This update for gleam fixes the following issues:

Changes in gleam:

• Update to 1.17.0:

  • Fixed security vulnerabilities:
    • Restrict custom documentation page path and source values so gleam docs build cannot escape the docs output directory or project root (bsc#1267396, CVE-2026-32685)
    • Restrict publication tarball creation so they cannot contain files from outside the project root (bsc#1267397, CVE-2026-42795)
    • Stricter deserialisation rules for files internal the build directory to reject corrupted data (bsc#1267398, CVE-2026-43965)
  • All features and bug fixes are extensively highlighted with examples in the upstream blog post at https://gleam.run/news/single-file-gleam-beam-programs-with-escript/ and changelog at https://github.com/gleam-lang/gleam/blob/v1.17.0/CHANGELOG.md some of the highlights include:
    • Various JavaScript code generation fixes and optimization
    • Various compiler error handling improvements
    • Ability to use the todo keyword in constants
    • Improved handling of Git monorepos during package management
    • Ability to create escripts from Gleam programs
    • Various language server improvements like reference highlighting, record hovering and code actions

• Update to 1.16.0:

  • Changelog v1.16.0: https://gleam.run/news/javascript-source-maps/

• Update to 1.15.1:

  • Changelog v1.12.0: https://gleam.run/news/no-more-dependency-management-headaches/
  • Changelog v1.13.0: https://gleam.run/news/formalising-external-apis/
  • Changelog v1.14.0: https://gleam.run/news/the-happy-holidays-2025-release/
  • Changelog v1.15.0: https://gleam.run/news/upgrading-hex-security/

• Replace deprecated "disabled" mode with "manual" in _service

• Update to 1.11.0:

  • The displaying of internal types in HTML documentation has been improved
  • A warning is now emitted when the same module is imported multiple times into the same module with different aliases
  • Fixed a bug where a bit array segment matching on a floating point number would match with NaN or Infinity on the JavaScript target
  • https://github.com/gleam-lang/gleam/blob/v1.11.1/CHANGELOG.md

• Update to 1.10.0:

  • Changelog: https://gleam.run/news/global-rename-and-find-references/

• skip unit tests that requires networking upon build

• Update to 1.9.0:

  • Changelog: https://gleam.run/news/hello-echo-hello-git/

• Update to 1.8.1:

• Fixed a metadata caching bug where accessors for opaque types could sometimes be used in other modules. (Louis Pilfold)
• Changelog: https://gleam.run/news/gleam-gets-rename-variable/

• Update to 1.7.0:

• Changelog: https://gleam.run/news/improved-performance-and-publishing/

• Update to 1.6.3:

• Fixed a bug where Gleam would be unable to compile to BEAM bytecode on older versions of Erlang/OTP. (yoshi)

• Update to 1.6.2:

• Fixed a bug where patterns in use expressions would not be checked to ensure that they were exhaustive. (Surya Rose)

• Update to 1.6.1:

• fix update use_manifest logic (Jason Sipula)
• 1.6.0 Changelog: https://gleam.run/news/context-aware-compilation/