CVE-2026-58404 (GCVE-0-2026-58404)

Vulnerability from cvelistv5 – Published: 2026-07-06 19:16 – Updated: 2026-07-06 19:16
VLAI
Title
Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings
Summary
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.
Severity
4.6 (Medium)
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
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
Impacted products
Vendor Product Version
gohugoio hugo Affected: >= v0.162.0, < v0.163.1
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "hugo",
          "vendor": "gohugoio",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= v0.162.0, \u003c v0.163.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 4.6,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-06T19:16:15.945Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv"
        },
        {
          "name": "https://github.com/gohugoio/hugo/pull/15020",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/gohugoio/hugo/pull/15020"
        },
        {
          "name": "https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372"
        },
        {
          "name": "https://github.com/gohugoio/hugo/releases/tag/v0.163.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/gohugoio/hugo/releases/tag/v0.163.1"
        }
      ],
      "source": {
        "advisory": "GHSA-r46f-3rpw-hxrv",
        "discovery": "UNKNOWN"
      },
      "title": "Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-58404",
    "datePublished": "2026-07-06T19:16:15.945Z",
    "dateReserved": "2026-06-30T18:19:58.379Z",
    "dateUpdated": "2026-07-06T19:16:15.945Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-58404\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-06T20:16:38.307\",\"lastModified\":\"2026-07-06T20:16:38.307\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"gohugoio\",\"product\":\"hugo\",\"versions\":[{\"version\":\"\u003e= v0.162.0, \u003c v0.163.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":4.6,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-918\"}]}],\"references\":[{\"url\":\"https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/gohugoio/hugo/pull/15020\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/gohugoio/hugo/releases/tag/v0.163.1\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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