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

> An attacker contributing content can use symlinks to read arbitrary files outside the project directory during Hugo builds, potentially disclosing sensitive data.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-100690, GHSA-gqg5-5gw3-54pq, GHSA-x3mx-cm49-8m9c, MINI-4qc6-2j6r-3x47, MINI-jv48-5x58-jq27, UBUNTU-CVE-2026-100690

## What is CVE-2026-100690?

CVE-2026-100690 is a high-severity path traversal vulnerability in gohugoio hugo, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-100690?

It affects 1 product.


Products: Gohugo Hugo.

## How do I fix CVE-2026-100690?

Upgrade to a fixed version.

## Is CVE-2026-100690 being exploited?

There is no known exploitation of CVE-2026-100690 in the wild and no public exploit code.

## Other vulnerabilities in gohugoio hugo

- [CVE-2026-75926](https://insights.sbomify.com/CVE-2026-75926/): Hugo 0.162.0 to 0.164.x - Node Permission Model Bypass via Default TailwindCSS Child-Process Grant (critical 9.3)
- [CVE-2026-100692](https://insights.sbomify.com/CVE-2026-100692/): Hugo before v0.166.0 Path Traversal via Symlinked Mount Roots (high 8.7)
- [CVE-2026-100693](https://insights.sbomify.com/CVE-2026-100693/): Hugo v0.162.0 before v0.166.0 IP-literal Deny Rule Bypass (high 8.6)
- [CVE-2020-26284](https://insights.sbomify.com/CVE-2020-26284/): Hugo can execute a binary from the current directory on Windows (high 7.7)
- [CVE-2026-50135](https://insights.sbomify.com/CVE-2026-50135/): Hugo: Symlink confinement bypass in resources.Get (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100690 and fix it if it is affected.

What it is: CVE-2026-100690 is a high-severity path traversal vulnerability in gohugoio hugo, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100690 in the wild and no public exploit code.

Affected product: gohugoio hugo. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-100690/ (Markdown: https://insights.sbomify.com/CVE-2026-100690/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100690
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100690
- OSV: https://osv.dev/vulnerability/CVE-2026-100690

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-100690/
Summaries are generated and may contain mistakes; the official description above is the record.