PT-2026-45757 · Gleam · Gleam

Louis Pilfold · Published 2026-06-02 · Updated 2026-06-02 · CVE-2026-43965

Positive Technologies (AI Summary)

CVSS v4.0

5.6

Medium

Base vector

AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Name of the Vulnerable Software and Affected Versions Gleam versions 0.18.0-rc1 through 1.17.0

Description A path traversal issue in the dependency management system allows for the recursive deletion of arbitrary directories. This occurs because package keys read from the build/packages/packages.toml file by the LocalPackages::read from disc function are passed without validation to paths.build packages package(). This process constructs a filesystem path by joining the project build directory with an attacker-controlled key, which is then passed to fs::delete directory (which calls remove dir all). Since the system does not verify if the path remains within the intended build/packages/ directory, both absolute paths and relative traversal sequences (such as ../) can be used to target and delete any directory on the victim's system when the gleam deps download command is executed on a project containing a malicious configuration file.

Recommendations Update Gleam to a version later than 1.17.0.

Exploit

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-43965

GHSA-JQVF-F6P2-WRV3

Affected Products

Gleam

References · 5

• 🔥 https://github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3 · Exploit
• https://osv.dev/vulnerability/EEF-CVE-2026-43965 · Vendor Advisory
• https://github.com/gleam-lang/gleam/commit/690ca069817bee5f77a28fc3e360627c1da19291 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-43965 · Security Note
• https://cna.erlef.org/cves/CVE-2026-43965.html · Note