Summary
Hugo: XSS via text/html content files
Commit: e41a06447d, Disallow HTML content by default
Affected versions: all Hugo versions prior to v0.162.0.
Fixed in: v0.162.0.
Severity: Low to Medium, depending on threat model. Not an issue if you fully trust every file under /content and every content adapter you load.
Description. Hugo accepts content files in several markup formats. Files mapped to the text/html media type (typically .html files under /content, or pages produced by a content adapter that sets content.mediaType = "text/html") had their body emitted verbatim into the rendered page. A site that ingests HTML content from an untrusted source, for example, a CMS-backed editor, a content adapter pulling from an external API, or an automated import pipeline, could therefore be served stored cross-site scripting.
Mitigation. v0.162.0 introduces a security.allowContent whitelist with text/html denied by default. Sites that intentionally author HTML content can opt back in:
[security]
allowContent = ['.*']
This only affects pages whose source file (or content adapter output) declares an HTML media type; Markdown, AsciiDoc, Org, Pandoc and reStructuredText content is unaffected.
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-50133? CVE-2026-50133 is a medium-severity cross-site scripting (XSS) vulnerability in github.com/gohugoio/hugo (go), affecting versions < 0.162.0. It is fixed in 0.162.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of github.com/gohugoio/hugo are affected by CVE-2026-50133? github.com/gohugoio/hugo (go) versions < 0.162.0 is affected.
- Is there a fix for CVE-2026-50133? Yes. CVE-2026-50133 is fixed in 0.162.0. Upgrade to this version or later.
- Is CVE-2026-50133 exploitable, and should I be worried? Whether CVE-2026-50133 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-50133 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-50133? Upgrade
github.com/gohugoio/hugoto 0.162.0 or later.