GHSA-q76j-gcg9-vxc6: Hugo Cross-Site Scripting Vulnerability

MODERATE
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CWE-79
Published
Advisory Summary

GHSA-q76j-gcg9-vxc6 is a MODERATE cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Hugo libraries in the Go ecosystem. The issue involves xss via unescaped code-fence language in default code block renderer. Remediation is available by upgrading affected packages to version 0.163.3.

GHSA-q76j-gcg9-vxc6 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-q76j-gcg9-vxc6
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Hugo
Package Ecosystem Go
Published Date
Last Updated

How to Fix GHSA-q76j-gcg9-vxc6

To remediate this vulnerability, upgrade all affected Hugo dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/gohugoio/hugo fixed: 0.163.3 
Upgrade github.com/gohugoio/hugo to 0.163.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/gohugoio/hugo

How to Check if You Are Affected

To determine whether your application is affected by GHSA-q76j-gcg9-vxc6, inspect your project dependencies for Hugo:

inspect dependencies for github.com/gohugoio/hugo

Analyze the terminal output to locate any version of Hugo in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.163.3), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Hugo, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Hugo's default code-block renderer wrote the Markdown code-fence language / 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 is not an issue if you fully trust every file under /content and every content adapter you load.

GHSA-q76j-gcg9-vxc6 Affected Hugo Versions

1 component(s)
Fixed Versions:
0.163.3
Product / Package Ecosystem Affected Versions Fixed Version
github.com/gohugoio/hugo
golang/github.com/gohugoio/hugo
Go
≥ 0.60.0
< 0.163.3
0.163.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/gohugoio/hugo/security/advisories/GHSA-q76j-gcg9-vxc6
Hugo Source Repository REPOSITORY
https://github.com/gohugoio/hugo

Frequently Asked Questions

What is GHSA-q76j-gcg9-vxc6?
GHSA-q76j-gcg9-vxc6 is a security vulnerability in Hugo involving XSS via unescaped code-fence language in default code block renderer under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Hugo versions are affected?
Affected versions include releases prior to 0.163.3 across affected packages: github.com/gohugoio/hugo.
What version fixes GHSA-q76j-gcg9-vxc6?
Upgrading to 0.163.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/gohugoio/hugo affected?
Yes, github.com/gohugoio/hugo is affected in releases prior to 0.163.3. Upgrade your dependency to 0.163.3 or later.
What CWE is associated with GHSA-q76j-gcg9-vxc6?
GHSA-q76j-gcg9-vxc6 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Go dependencies for GHSA-q76j-gcg9-vxc6?
Run the dependency tree command: 'inspect dependencies for github.com/gohugoio/hugo'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q76j-gcg9-vxc6",
  "modified" : "2026-06-19T17:45:27Z",
  "published" : "2026-06-19T17:45:27Z",
  "aliases" : [ ],
  "summary" : "Hugo: XSS via unescaped code-fence language in default code block renderer",
  "details" : "Hugo's default code-block renderer wrote the Markdown code-fence language / 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.\n\nThis is not an issue if you fully trust every file under /content and every content adapter you load.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/gohugoio/hugo"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.60.0"
      }, {
        "fixed" : "0.163.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/gohugoio/hugo/security/advisories/GHSA-q76j-gcg9-vxc6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/gohugoio/hugo"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T17:45:27Z",
    "nvd_published_at" : null
  }
}