CVE-2026-58404Public exploitNetwork attack vector

Internal-service access via alternate IPv4 encodings

Published Jul 6, 2026 · Updated Jul 6, 2026

SSRF in Hugo 0.162.0 through 0.163.0 allows remote attackers to make build-time requests to internal services via encoded IPv4 hosts. The security.http.urls check evaluates only dotted-decimal hosts before resources.GetRemote requests or redirects, so cgo resolution converts integer, hex, or octal forms after the deny decision. Exposure requires an attacker-influenced template URL, a cgo system resolver, and reliance on the default policy; reachable targets include loopback, intranet, and cloud-metadata endpoints.

CVSS severity4.6
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Hugo 0.162.0 through 0.163.0 allows remote attackers to make build-time requests to internal services via encoded IPv4 hosts. The security.http.urls check evaluates only dotted-decimal hosts before resources.GetRemote requests or redirects, so cgo resolution converts integer, hex, or octal forms after the deny decision. Exposure requires an attacker-influenced template URL, a cgo system resolver, and reliance on the default policy; reachable targets include loopback, intranet, and cloud-metadata endpoints.

The record

CVE
CVE-2026-58404
Published
Jul 6, 2026
Updated
Jul 6, 2026
Vendor
Hugo Authors
Product
Hugo
Classifications
CWE-918, CAPEC-664, T1552.005
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= v0.162.0, < v0.163.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Hugo Authors · Hugoversion=>= v0.162.0, < v0.163.1

Published CVSS scores

6.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
4.6GitHub CNACVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery
T1552.005Unsecured Credentials Cloud Instance Metadata API

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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