Skip to content
Heist/ feed
Back to feed
Medium

vnu — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2025-15104

Nu Html Checker (validator.nu) contains a restriction bypass that allows remote attackers to make the server perform arbitrary HTTP/HTTPS requests to internal resources, including localhost services. While the validator implements hostname-based protections to block direct access to localhost and 127.0.0.1, these controls can be bypassed using DNS rebinding techniques or domains that resolve to loopback addresses.This issue affects The Nu Html Checker (vnu): latest (commit 23f090a11bab8d0d4e698f1ffc197a4fe226a9cd).

Products
vnu
Affected versions
23.4.11+dfsg-5, 26.5.2.1+dfsg-1, 26.5.2.1+dfsg-2, 26.8.15.1+dfsg-1
Fixed versions
Not specified
CVEs
CVE-2025-15104
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 01:25 UTC · Revision 1

Source evidence

UBUNTU-CVE-2025-15104

core-osv · Original source

Published 16 Jan 2026, 14:15 UTC

Nu Html Checker (validator.nu) contains a restriction bypass that allows remote attackers to make the server perform arbitrary HTTP/HTTPS requests to internal resources, including localhost services. While the validator implements hostname-based protections to block direct access to localhost and 127.0.0.1, these controls can be bypassed using DNS rebinding techniques or domains that resolve to loopback addresses.This issue affects The Nu Html Checker (vnu): latest (commit 23f090a11bab8d0d4e698f1ffc197a4fe226a9cd).

osv:UBUNTU-CVE-2025-15104

vnu

Fixed versions: Not specified

Complete source record
{
  "id": "3b89d935155cd5010caa39d150dbe2ce2db36c50a8df489293ad289998248fb0",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2025-15104",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2025-15104",
    "summary": "Nu Html Checker (validator.nu) contains a restriction bypass that allows remote attackers to make the server perform arbitrary HTTP/HTTPS requests to internal resources, including localhost services. While the validator implements hostname-based protections to block direct access to localhost and 127.0.0.1, these controls can be bypassed using DNS rebinding techniques or domains that resolve to loopback addresses.This issue affects The Nu Html Checker (vnu): latest (commit 23f090a11bab8d0d4e698f1ffc197a4fe226a9cd).",
    "evidence": "osv:UBUNTU-CVE-2025-15104",
    "products": [
      {
        "name": {
          "value": "vnu",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "23.4.11+dfsg-5",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "26.5.2.1+dfsg-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "26.5.2.1+dfsg-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "26.8.15.1+dfsg-1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2025-15104",
      "aliases": [
        "UBUNTU-CVE-2025-15104"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N"
        },
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "vnu",
            "purl": "pkg:deb/ubuntu/vnu?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "23.4.11+dfsg-5",
            "26.5.2.1+dfsg-1",
            "26.5.2.1+dfsg-2",
            "26.8.15.1+dfsg-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-15104.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libvnu-java",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "libvnu-java-common",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu-client",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu-common",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu-jetty12",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu-server",
                "binary_version": "26.8.15.1+dfsg-1"
              },
              {
                "binary_name": "vnu-tomcat11",
                "binary_version": "26.8.15.1+dfsg-1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:56:48.368570140Z",
      "provider": "osv",
      "upstream": [
        "CVE-2025-15104"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2025-15104",
        "https://www.cve.org/CVERecord?id=CVE-2025-15104",
        "https://github.com/validator/validator/issues/2033",
        "https://github.com/validator/validator/commit/b95c4190258db2769cff67cc09d323432bd7a99e"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2025-15104",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 356331,
  "published_at": "2026-01-16T14:15:00+00:00"
}