{"id":"CVE-2026-58404","aliases":["DEBIAN-CVE-2026-58404","EUVD-2026-41918","GHSA-r46f-3rpw-hxrv","GO-2026-5606","RHSA-2026:36862","UBUNTU-CVE-2026-58404"],"status":"published","title":"Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings","description":"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":{"version":"4.0","score":4.6,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00368,"percentile":0.30876,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-918"],"published":"2026-06-19T19:18:14Z","modified":"2026-10-28T02:30:59Z","fixes":[{"ecosystem":"Go","package":"github.com/gohugoio/hugo","fixed_in":["0.163.1"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"hugo","fixed_in":["0.165.0-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/gohugoio/hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.162.0"},{"fixed":"0.163.1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.165.0-1"}]}],"versions":["0.131.0-1","0.131.0-2","0.150.0-1","0.150.1-1","0.151.0-1","0.151.1-1","0.151.2-1","0.152.1-1","0.152.2-1","0.153.0-1","0.153.1-1","0.153.1-2","0.153.1-3","0.153.2-1","0.154.1-1","0.154.2-1","0.154.2-2","0.154.3-1","0.154.5-1","0.155.1-1","0.155.2-1","0.155.3-1","0.157.0-1","0.157.0-2","0.157.0-3","0.158.0-1","0.158.0-2","0.158.0-3","0.159.0-1","0.159.1-1","0.159.2-1","0.160.0-1","0.160.0-2","0.160.1-1","0.161.0-1","0.161.1-1","0.162.1-1","0.162.1-2","0.162.1-3","0.162.1-4","0.162.1-5","0.162.1-6","0.162.1-7"]},{"source":"osv","ecosystem":"Go","package":"github.com/gohugoio/hugo","ranges":[{"type":"SEMVER","events":[{"introduced":"0.162.0"},{"fixed":"0.163.1"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/gohugoio/hugo","ranges":[{"type":"SEMVER","events":[{"introduced":"0.162.0"},{"fixed":"0.163.1"}]}]},{"source":"osv","ecosystem":"Red Hat:hummingbird:1","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:0.163.3-0.1.hum1"}]}],"bundled":4},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.15+git20160109.147.dd1d655-1","0.15+git20160109.147.dd1d655-2","0.15+git20160128.179.5def6d9-1","0.15+git20160206.203.ed23711-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.25.1-2","0.26-1","0.35-1","0.37.1-1","0.38-1","0.39-1","0.40-1","0.40.1-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.57.2-1","0.58.3-1","0.59.1-1.1","0.68.3-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.80.0-6","0.89.4-2","0.90.0-1","0.90.1-1","0.91.0-1","0.91.2-1","0.92.0-1","0.92.1-1build1","0.92.2-1","0.92.2-1ubuntu0.1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.113.0-3","0.119.0-2","0.120.3-1","0.120.4-1","0.121.2-1","0.122.0-1","0.123.7-1build1","0.123.7-1ubuntu0.1","0.123.7-1ubuntu0.2","0.123.7-1ubuntu0.2+esm1","0.123.7-1ubuntu0.3","0.123.7-1ubuntu0.3+esm1","0.123.7-1ubuntu0.3+esm2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.131.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.154.5-1","0.162.1-5","0.162.1-7"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"hugo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.131.0-1","0.152.2-1","0.153.1-3","0.153.2-1","0.154.2-2","0.154.3-1","0.154.5-1"]}],"products":[{"vendor":"gohugo","product":"hugo"},{"vendor":"gohugoio","product":"hugo"}],"references":[{"url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-r46f-3rpw-hxrv","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web","article","report"]},{"url":"https://github.com/gohugoio/hugo/pull/15020","tags":["x_refsource_MISC","Issue Tracking","fix","article","report"]},{"url":"https://github.com/gohugoio/hugo/commit/a00b5c72ac57afe26df6688ece3ca544a56df372","tags":["x_refsource_MISC","Patch","fix","article","report"]},{"url":"https://github.com/gohugoio/hugo/releases/tag/v0.163.1","tags":["x_refsource_MISC","Release Notes","web","article","report"]},{"url":"https://github.com/advisories/GHSA-r46f-3rpw-hxrv"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58404.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58404","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-58404","tags":["advisory"]},{"url":"https://github.com/gohugoio/hugo","tags":["package"]},{"url":"https://access.redhat.com/errata/RHSA-2026:36862","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-58402","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-58403","tags":["report"]},{"url":"https://access.redhat.com/security/updates/classification/","tags":["article"]},{"url":"https://images.redhat.com/","tags":["article"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-50133","tags":["report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-58404","tags":["report"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_36862.json","tags":["advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2497463","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-50133","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50133","tags":["advisory"]},{"url":"https://github.com/gohugoio/hugo/commit/e41a06447daa3071a01f333fdcec0a5153c3c8d1","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/releases/tag/v0.162.0","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-c54g-xjwj-8g82","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2497467","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-58402","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58402","tags":["advisory"]},{"url":"https://github.com/gohugoio/hugo/commit/ce1a7e0bce3713af40496ded3c2c0ceeed49231d","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/pull/15051","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/releases/tag/v0.163.3","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-q76j-gcg9-vxc6","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2497460","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-58403","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58403","tags":["advisory"]},{"url":"https://github.com/gohugoio/hugo/commit/cf9c8f93ca2a2838ce378f9e36d052ac2f79e229","tags":["article"]},{"url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-c3wq-j5vh-68rc","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2497450","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-58404","tags":["advisory","report"]},{"url":"https://ubuntu.com/security/CVE-2026-58404","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-58404","title":"Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings","description":"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.","status":"published","published":"2026-07-06T19:16:15.945Z","modified":"2026-07-07T15:08:53.514Z","cvss":[{"version":"4.0","score":4.6,"vector":"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","level":"medium","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T13:47:39.876248Z"}],"euvd":[{"id":"EUVD-2026-41918","description":"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.","status":"published","published":"2026-07-06T19:16:15Z","modified":"2026-07-07T15:08:53Z","cvss":[{"version":"4.0","score":4.6,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T18:20:11.925616Z"}],"ghsa":[{"id":"GHSA-r46f-3rpw-hxrv","title":"Hugo: security.http.urls deny rules bypassed by alternate IPv4 encodings (SSRF)","description":"### Impact\n\n  The default `security.http.urls` policy denies requests to loopback, internal,\n  and cloud-metadata IPv4 literals (e.g. `http://127.0.0.1/`,\n  `http://169.254.169.254/`). The deny rule only matched dotted-decimal notation,\n  so alternate IPv4 encodings of the same addresses — integer, hex, or octal,\n  which contain no dot — passed the policy:\n\n  - `http://2130706433/` → `127.0.0.1`\n  - `http://2852039166/` → `169.254.169.254` (cloud metadata)\n  - `http://0x7f000001/`, `http://017700000001/`, `http://0/`\n\n  When a template passes an untrusted or data-derived URL to\n  `resources.GetRemote` and the host platform uses the\n  cgo system resolver, these encodings resolve to the blocked address — allowing\n  build-time server-side requests to loopback and internal services, including the\n  cloud-metadata endpoint in hosted/CI builds. The same check is reused on\n  redirects, so the gap also applies to each redirect hop.\n\n  This affects sites that rely on `security.http.urls` as a security boundary\n  while fetching attacker-influenced remote URLs; it does not affect sites that\n  fully trust the URLs they fetch.\n\n  ### Patches\n\n  Fixed in **v0.163.1**. Integer/hex/octal IPv4 hosts are now canonicalized to\n  dotted-decimal before the policy is applied, so every encoding of an address is\n  treated alike. No configuration change is required.\n\n  ### Workarounds\n\n  Avoid passing untrusted URLs to `resources.GetRemote`, or\n  tighten `security.http.urls` to an explicit allow-list of trusted hosts.\n\n  ### Affected versions\n\n  v0.162.0 – v0.163.0 (patched in v0.163.1).","status":"published","published":"2026-06-19T19:18:14Z","modified":"2026-06-19T19:18:16Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:40:30.53004Z"}],"nvd":[{"id":"CVE-2026-58404","description":"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.","status":"published","published":"2026-07-06T20:16:38.307Z","modified":"2026-10-25T20:10:00.147Z","cvss":[{"version":"4.0","score":4.6,"vector":"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","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:12:28.040501Z"}],"osv":[{"id":"CVE-2026-58404","title":"Hugo security.http.urls deny rules bypassed by alternate IPv4 encodings","description":"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.","status":"published","published":"2026-07-06T19:16:15.945Z","modified":"2026-10-28T02:30:59.341416574Z","cvss":[{"version":"4.0","score":4.6,"vector":"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","level":"medium"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:45:12.496548Z"},{"id":"DEBIAN-CVE-2026-58404","description":"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.","status":"published","published":"2026-07-06T20:16:38.307Z","modified":"2026-10-26T11:47:29.641075503Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:57.590991Z"},{"id":"GHSA-r46f-3rpw-hxrv","title":"Hugo: security.http.urls deny rules bypassed by alternate IPv4 encodings (SSRF)","description":"### Impact\n\n  The default `security.http.urls` policy denies requests to loopback, internal,\n  and cloud-metadata IPv4 literals (e.g. `http://127.0.0.1/`,\n  `http://169.254.169.254/`). The deny rule only matched dotted-decimal notation,\n  so alternate IPv4 encodings of the same addresses — integer, hex, or octal,\n  which contain no dot — passed the policy:\n\n  - `http://2130706433/` → `127.0.0.1`\n  - `http://2852039166/` → `169.254.169.254` (cloud metadata)\n  - `http://0x7f000001/`, `http://017700000001/`, `http://0/`\n\n  When a template passes an untrusted or data-derived URL to\n  `resources.GetRemote` and the host platform uses the\n  cgo system resolver, these encodings resolve to the blocked address — allowing\n  build-time server-side requests to loopback and internal services, including the\n  cloud-metadata endpoint in hosted/CI builds. The same check is reused on\n  redirects, so the gap also applies to each redirect hop.\n\n  This affects sites that rely on `security.http.urls` as a security boundary\n  while fetching attacker-influenced remote URLs; it does not affect sites that\n  fully trust the URLs they fetch.\n\n  ### Patches\n\n  Fixed in **v0.163.1**. Integer/hex/octal IPv4 hosts are now canonicalized to\n  dotted-decimal before the policy is applied, so every encoding of an address is\n  treated alike. No configuration change is required.\n\n  ### Workarounds\n\n  Avoid passing untrusted URLs to `resources.GetRemote`, or\n  tighten `security.http.urls` to an explicit allow-list of trusted hosts.\n\n  ### Affected versions\n\n  v0.162.0 – v0.163.0 (patched in v0.163.1).","status":"published","published":"2026-06-19T19:18:14Z","modified":"2026-07-24T19:11:46.394705101Z","cvss":[{"version":"4.0","score":7.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:46:55.122811Z"},{"id":"RHSA-2026:36862","title":"Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update","status":"published","published":"2026-07-29T10:09:26Z","modified":"2026-09-08T10:13:09Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:53:19.963895Z"},{"id":"UBUNTU-CVE-2026-58404","description":"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.","status":"published","published":"2026-07-06T20:16:00Z","modified":"2026-10-17T12:59:13.901390825Z","cvss":[{"version":"4.0","score":4.6,"vector":"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","level":"medium"},{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T16:56:41.911783Z"},{"id":"GO-2026-5606","title":"Hugo: security.http.urls deny rules bypassed by alternate IPv4 encodings (SSRF) in github.com/gohugoio/hugo","description":"Hugo: security.http.urls deny rules bypassed by alternate IPv4 encodings (SSRF) in github.com/gohugoio/hugo","status":"published","published":"2026-07-24T18:35:55Z","modified":"2026-07-24T19:11:46.394705101Z","updated_at":"2026-11-02T15:47:02.556545Z"}]}}