Hugo is a static site generator. From v0.162.0 through v0.163.0, the default security.http.urls policy denies requests to loopback, internal, and cloud-metadata IPv4 literals, but the deny rule only matched dotted-decimal notation, so alternate IPv4 encodings of the same addresses, including integer, hex, or octal, passed the policy. When a template passes an untrusted or data-derived URL to resources.GetRemote and the host platform uses the cgo system resolver, these encodings resolve to the blocked address, allowing build-time server-side requests to loopback and internal services, including the cloud-metadata endpoint in hosted or CI builds; the same check is reused on redirects, so the gap also applies to each redirect hop. This issue is fixed in v0.163.1.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372 Patch
- https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 4.6 · gohugoNVD modified 2026-10-25 20:10
Affected (CPE criteria) 1
cpe:2.3:a:gohugo:hugo:*:*:*:*:*:*:*:*
References 4
- https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372 Patch
- https://github.com/gohugoio/hugo/pull/15020 Issue Tracking
- https://github.com/gohugoio/hugo/releases/tag/v0.163.1 Release Notes
- https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv Mitigation, Vendor Advisory