CVE-2026-35166: Hugo Certain Markdown Links Are Not Vulnerability

MODERATE
Advisory Identifier: GHSA-mcv8-8m8x-48pg
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CWE-79
Published
Advisory Summary

CVE-2026-35166 is a MODERATE certain markdown links are not vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Hugo libraries in the Go ecosystem. The issue involves certain markdown links are not properly escaped. Remediation is available by upgrading affected packages to version 0.159.2.

CVE-2026-35166 at a Glance

CVE Identifier CVE-2026-35166
GHSA Identifier GHSA-mcv8-8m8x-48pg
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 CVE-2026-35166

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: 0.159.2 
Upgrade github.com/gohugoio/hugo to 0.159.2
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 CVE-2026-35166, 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 0.159.2), 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

### Impact Links and image links in the default markdown to HTML renderer are not properly escaped. Hugo users who trust their Markdown content or have custom render hooks for links and images are not affected. ### Patches Patched in v0.159.2 ### Workarounds Create custom render hooks for links and images in a Hugo theme/project.

CVE-2026-35166 Affected Hugo Versions

1 component(s)
Fixed Versions:
0.159.2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/gohugoio/hugo
golang/github.com/gohugoio/hugo
Go
≥ 0.60.0
< 0.159.2
0.159.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/gohugoio/hugo/security/advisories/GHSA-mcv8-8m8x-48pg
NVD — CVE-2026-35166 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35166
Security Fix Commit FIX COMMIT
https://github.com/gohugoio/hugo/commit/479fe6c654937a850b65e74551dc4e857d52898f
Hugo Source Repository REPOSITORY
https://github.com/gohugoio/hugo

Frequently Asked Questions

What is CVE-2026-35166?
CVE-2026-35166 is a security vulnerability in Hugo involving Certain markdown links are not properly escaped 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 0.159.2 across affected packages: github.com/gohugoio/hugo.
What version fixes CVE-2026-35166?
Upgrading to 0.159.2 (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 0.159.2. Upgrade your dependency to 0.159.2 or later.
What CWE is associated with CVE-2026-35166?
CVE-2026-35166 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 CVE-2026-35166?
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-mcv8-8m8x-48pg",
  "modified" : "2026-04-06T23:42:22Z",
  "published" : "2026-04-03T23:38:19Z",
  "aliases" : [ "CVE-2026-35166" ],
  "summary" : "Hugo: Certain markdown links are not properly escaped",
  "details" : "### Impact\nLinks and image links in the default markdown to HTML renderer are not properly escaped. Hugo users who trust their Markdown content or have custom render hooks for links and images are not affected.\n\n### Patches\nPatched in  v0.159.2\n\n### Workarounds\nCreate custom render hooks for links and images in a Hugo theme/project.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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" : "0.159.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/gohugoio/hugo/security/advisories/GHSA-mcv8-8m8x-48pg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35166"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/gohugoio/hugo/commit/479fe6c654937a850b65e74551dc4e857d52898f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/gohugoio/hugo"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-03T23:38:19Z",
    "nvd_published_at" : "2026-04-06T18:16:43Z"
  }
}