CVE-2026-35166
CVE-2026-35166 is a Cross-site Scripting (XSS) vulnerability in github.com/gohugoio/hugo. O3 Security confirms whether CVE-2026-35166 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Hugo does not properly escape some Markdown links
Blast Radius
github.com/gohugoio/hugoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Hugo is a static site generator. From 0.60.0 to before 0.159.2, 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. This vulnerability is fixed in 0.159.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/gohugoio/hugo | ≥ 0.60.0&&< 0.159.2 | 0.159.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/gohugoio/hugo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/gohugoio/hugo to 0.159.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35166 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-35166 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-35166. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35166 in your dependencies?
O3 detects CVE-2026-35166 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.