CVE-2026-58402 Hugo default code block renderer XSS via unescaped code-fence language
Attackers can inject malicious scripts via unescaped code-fence language attributes in Hugo-generated pages, leading to cross-site scripting.
- 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
What is CVE-2026-58402?
CVE-2026-58402 is a medium-severity cross-site scripting vulnerability in gohugoio hugo, published on 6 Jul 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 is a static site generator. From 0.60.0 until 0.163.3, Hugo's default code-block renderer wrote the Markdown code-fence language or info-string into the code class="language-…" data-lang="…" wrapper without HTML escaping. A fence info-string containing a quote and a script payload breaks out of the attribute and injects a live script element. This issue is fixed in 0.163.3.
Weakness: CWE-79
Which versions are affected by CVE-2026-58402?
3 open source packages ship an affected version, including github.com/gohugoio/hugo. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/gohugoio/hugo Go | From 0.60.0 | 0.163.3 |
github.com/gohugoio/hugo Go | From 0.60.0 | 0.163.3 |
github.com/gohugoio/hugo Go | From 0.60.0 | 0.163.3 |
Products include Gohugo Hugo.
How do I fix CVE-2026-58402?
Upgrade github.com/gohugoio/hugo to 0.163.3 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-58402 being exploited?
There is no known exploitation of CVE-2026-58402 in the wild and no public exploit code.
Other vulnerabilities in gohugoio hugo
- CVE-2026-75926 Hugo 0.162.0 to 0.164.x - Node Permission Model Bypass via Default TailwindCSS Child-Process Grant
- CVE-2026-100690 Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks
- CVE-2026-100692 Hugo before v0.166.0 Path Traversal via Symlinked Mount Roots
- CVE-2026-100693 Hugo v0.162.0 before v0.166.0 IP-literal Deny Rule Bypass
- CVE-2020-26284 Hugo can execute a binary from the current directory on Windows
Sources
Also known as DEBIAN-CVE-2026-58402, GHSA-q76j-gcg9-vxc6, GO-2026-5569, JLSEC-2026-796, MINI-7gfj-7qmx-h9j9, MINI-7mg8-q87g-wqv4 and 3 more.