# CVE-2026-109597: Hugo v0.60.0 before v0.167.0 Stored XSS via Table of Contents Heading IDs

> Markdown authors can inject malicious HTML via crafted heading IDs in Hugo's Table of Contents, leading to stored XSS on rendered pages.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-109597, GHSA-hh58-7hgh-xf3r, GHSA-wcpj-vcvm-j4pg, MINI-f2w5-wg5p-5wm3, MINI-v3gj-8f92-2f35, UBUNTU-CVE-2026-109597

## What is CVE-2026-109597?

CVE-2026-109597 is a medium-severity cross-site scripting vulnerability in gohugoio hugo, published on 12 Oct 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Hugo from v0.60.0 before v0.167.0 contains a stored cross-site scripting vulnerability that allows Markdown content authors to inject HTML by supplying crafted explicit heading IDs. Attackers can break out of the unescaped href attribute in .TableOfContents or .Fragments.ToHTML output to inject elements with event handlers into rendered pages.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-109597?


## How do I fix CVE-2026-109597?

Upgrade to a fixed version.

## Is CVE-2026-109597 being exploited?

There is no known exploitation of CVE-2026-109597 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109597 and fix it if it is affected.

What it is: CVE-2026-109597 is a medium-severity cross-site scripting vulnerability in gohugoio hugo, published on 12 Oct 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-109597 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-2026-109597/ (Markdown: https://insights.sbomify.com/CVE-2026-109597/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109597
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109597
- OSV: https://osv.dev/vulnerability/CVE-2026-109597

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109597/
Summaries are generated and may contain mistakes; the official description above is the record.