SSRF in Gohugo Hugo

CVE-2026-58404

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-58404: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-58404?
CVE-2026-58404 is a medium-severity vulnerability in Gohugo Hugo, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.8/10. Published 2026-07-06.
How severe is CVE-2026-58404?
Medium severity. CVSS v3 base score is 6.8 out of 10.