Description
Symlink following vulnerability in Gleam's Hex package export allows files outside the project root to be embedded in the generated package tarball.

The file collection helpers (gleam_files, native_files, private_files) in compiler-cli/src/fs.rs use follow_links(true) when walking publishable directories such as src/ and priv/. The collected paths are added to the package archive via add_path_to_tar in compiler-cli/src/publish.rs without verifying that the resolved target remains within the project root. A symlink placed under a publishable directory will cause gleam export hex-tarball or gleam publish to embed the contents of the symlink target into the generated Hex package.

An attacker with write access to the project repository can place a symlink in src/ or priv/ pointing to an arbitrary file. When a maintainer or CI pipeline runs gleam publish or gleam export hex-tarball, local files readable by the publisher (such as secrets, tokens, or SSH keys) are silently embedded into the published package artifact.

This issue affects Gleam from 0.10.0-rc1 until 1.17.0.
Published: 2026-06-02
Score: 5.1 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

Vendor Workaround

* Avoid running gleam publish or gleam export hex-tarball on untrusted projects * Review the contents of src/ and priv/ for unexpected symlinks before publishing * Run publishing commands in a restricted or isolated environment (e.g. containers)

Tracking

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Advisories

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History

Tue, 02 Jun 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 02 Jun 2026 14:15:00 +0000

Type Values Removed Values Added
Description Symlink following vulnerability in Gleam's Hex package export allows files outside the project root to be embedded in the generated package tarball. The file collection helpers (gleam_files, native_files, private_files) in compiler-cli/src/fs.rs use follow_links(true) when walking publishable directories such as src/ and priv/. The collected paths are added to the package archive via add_path_to_tar in compiler-cli/src/publish.rs without verifying that the resolved target remains within the project root. A symlink placed under a publishable directory will cause gleam export hex-tarball or gleam publish to embed the contents of the symlink target into the generated Hex package. An attacker with write access to the project repository can place a symlink in src/ or priv/ pointing to an arbitrary file. When a maintainer or CI pipeline runs gleam publish or gleam export hex-tarball, local files readable by the publisher (such as secrets, tokens, or SSH keys) are silently embedded into the published package artifact. This issue affects Gleam from 0.10.0-rc1 until 1.17.0.
Title Symlink Following in Hex Package Export Allows Embedding Files Outside Project Root
First Time appeared Gleam-lang
Gleam-lang gleam
Weaknesses CWE-59
CPEs cpe:2.3:a:gleam-lang:gleam:*:*:*:*:*:*:*:*
Vendors & Products Gleam-lang
Gleam-lang gleam
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

Gleam-lang Gleam
cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-06-02T15:04:35.767Z

Reserved: 2026-04-29T18:06:33.251Z

Link: CVE-2026-42795

cve-icon Vulnrichment

Updated: 2026-06-02T15:03:56.544Z

cve-icon NVD

Status : Deferred

Published: 2026-06-02T14:16:53.883

Modified: 2026-06-02T14:46:08.900

Link: CVE-2026-42795

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses