{"id":"CVE-2026-43965","title":"Path traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content.\n\nPackage keys read from build/packages/packages.toml by LocalPackages::read_from_disc a…","summary":"Path traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content.\n\nPackage keys read from build/packages/packages.toml by LocalPackages::read_from_disc a…","severity":"medium","cvss":5.6,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-22"],"vendor":"Gleam","product":"gleam","affected":["gleam >= 0.18.0-rc1 < 1.17.0","gleam-lang/gleam >= 0.18.0-rc1 < 1.17.0","gleam-lang/gleam >= ed7aec0484f10d60978b63788c8a6497590855ab < 690ca069817bee5f77a28fc3e360627c1da19291","gleam-lang/gleam >= v0.18.0-rc1-elixir < v1.17.0-elixir","gleam-lang/gleam >= v0.18.0-rc1-erlang < v1.17.0-erlang","gleam-lang/gleam >= v0.18.0-rc1-node < v1.17.0-node","gleam-lang/gleam >= v0.18.0-rc1-node-slim < v1.17.0-node-slim","gleam-lang/gleam >= v0.18.0-rc1-elixir-slim < v1.17.0-elixir-slim","gleam-lang/gleam >= v0.18.0-rc1-erlang-slim < v1.17.0-erlang-slim","gleam-lang/gleam >= v0.18.0-rc1-erlang-alpine < v1.17.0-erlang-alpine","gleam-lang/gleam >= v0.18.0-rc1-elixir-alpine < v1.17.0-elixir-alpine","gleam-lang/gleam >= v0.18.0-rc1-node-alpine < v1.17.0-node-alpine","gleam-lang/gleam >= v0.18.0-rc1-scratch < v1.17.0-scratch"],"published":"2026-06-02","updated":"2026-09-08","sourceUpdated":"2026-09-08T01:17:30.670","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-43965","references":[{"url":"https://cna.erlef.org/cves/CVE-2026-43965.html","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/gleam-lang/gleam/commit/690ca069817bee5f77a28fc3e360627c1da19291","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-43965","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-06-02T15:07:44.667204Z"},"cvssSource":"cna","epss":0.00229,"epssPercentile":0.13949,"ingestedAt":"2026-09-08T13:33:24.844Z","slug":"CVE-2026-43965","body":"## Overview\n\nPath traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content.\n\nPackage 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.\n\nAn 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.\n\nThis issue affects Gleam from 0.18.0-rc1 until 1.17.0.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":30.8,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":5221,"id":"CVE-2026-43965","ts":1788887254137,"field":"exploit_available","old":"false","new":"true"},{"seq":5220,"id":"CVE-2026-43965","ts":1788887254137,"field":"cvss","old":null,"new":"5.6"},{"seq":5219,"id":"CVE-2026-43965","ts":1788887254137,"field":"severity","old":"none","new":"medium"},{"seq":4104,"id":"CVE-2026-43965","ts":1788886370000,"field":"exploit_available","old":"true","new":"false"},{"seq":4103,"id":"CVE-2026-43965","ts":1788886370000,"field":"cvss","old":"5.6","new":null},{"seq":4102,"id":"CVE-2026-43965","ts":1788886370000,"field":"severity","old":"medium","new":"none"},{"seq":2880,"id":"CVE-2026-43965","ts":1788883036329,"field":"exploit_available","old":"false","new":"true"},{"seq":2879,"id":"CVE-2026-43965","ts":1788883036329,"field":"cvss","old":null,"new":"5.6"},{"seq":2878,"id":"CVE-2026-43965","ts":1788883036329,"field":"severity","old":"none","new":"medium"},{"seq":1909,"id":"CVE-2026-43965","ts":1788882439410,"field":"exploit_available","old":"true","new":"false"},{"seq":1908,"id":"CVE-2026-43965","ts":1788882439410,"field":"cvss","old":"5.6","new":null},{"seq":1907,"id":"CVE-2026-43965","ts":1788882439410,"field":"severity","old":"medium","new":"none"},{"seq":249,"id":"CVE-2026-43965","ts":1788881642781,"field":"exploit_available","old":"false","new":"true"},{"seq":248,"id":"CVE-2026-43965","ts":1788881642781,"field":"cvss","old":null,"new":"5.6"},{"seq":247,"id":"CVE-2026-43965","ts":1788881642781,"field":"severity","old":"none","new":"medium"}]}