Medium 4.6Published Jul 6, 2026

CVE-2026-58404Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings

Updated under an hour ago (Oct 26, 2026, 11:23 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for gohugoio hugo

Exploited in the last 30 days

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.

CVSS: 4.6 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
Weakness (CWE): CWE-918
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Jul 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

gohugoio hugo gohugoio:hugo (from the name)	from 0.162.0, < v0.163.1	CNA record
gohugo hugo gohugo:hugo	from 0.162.0 before 0.163.1	NVD

References

https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrvx-refsource-confirm, mitigation, vendor-advisory
https://github.com/gohugoio/hugo/pull/15020x-refsource-misc, issue-tracking
https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372x-refsource-misc, patch
https://github.com/gohugoio/hugo/releases/tag/v0.163.1x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.