Vulnerability · Published Sep 26, 2026 · Assigned by VulnCheck
CVE-2026-100690Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks
High 7.5
In plain English
A high-severity security flaw in hugo from gohugoio. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | hugo | 0.166.0-1 | DEBIAN-CVE-2026-100690 |
| Ubuntu:22.04:LTS | hugo | no fix listed | UBUNTU-CVE-2026-100690 |
| Ubuntu:26.04:LTS | hugo | no fix listed | UBUNTU-CVE-2026-100690 |
| Ubuntu:26.10 | hugo | no fix listed | UBUNTU-CVE-2026-100690 |
Affected products (as reported)
Weakness: CWE-59 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- GitHub Security Advisory (GHSA-x3mx-cm49-8m9c) vendor-advisory
- VulnCheck Advisory: Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks third-party-advisory