fast-uri vulnerable to host confusion via unchecked WHATWG host canonicalization

{
  "id": "2b51cbb46fda84b6eb6d4bf6d962e6741b90ae162f8de4dd3866165a968e8583",
  "url": "https://osv.dev/vulnerability/GHSA-wjr9-j795-jxcr",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "fast-uri vulnerable to host confusion via unchecked WHATWG host canonicalization",
    "summary": "### Impact `fast-uri` versions `>= 2.4.2, <= 2.4.7`, `>= 3.1.3, <= 3.1.8`, and `>= 4.0.1, <= 4.2.2` can silently rewrite the host of an HTTP-family URL (`http`, `https`, `ws`, `wss`, or any scheme with `domainHost: true`). For those schemes `canonicalizeHost()` passes the parsed host to the WHATWG `URL` parser and adopts its `.hostname` without checking that the parser read the whole input as a host. RFC 3986 permits `@` inside the host group and the WHATWG parser strips TAB, LF, and CR, so the authority `fast-uri` reports is rewritten by that second parser with no `error` set: data before an `@` is dropped and whitespace is removed. For example, `fast-uri` parses `http://a@b@evil.example/` to host `evil.example` (dropping the `b` segment), and a host containing a raw TAB, CR, or LF has those characters stripped. `equal()` then treats a whitespace-smuggled host as the same as the clean one, and `resolve()` rewrites the authority the same way. Applications that use `fast-uri` to enforce host-based policy (denylists, loopback filtering, redirect validation, outbound proxy routing) on one representation, such as the raw input, see a policy/use desync: the canonical host `fast-uri` returns differs from what was checked, and traffic can be steered to an unintended destination. ### Patches Upgrade to `fast-uri` `2.4.8`, `3.1.9`, or `4.2.3`. ### Workarounds Reject URIs whose authority contains more than one `@`, or contains TAB, CR, or LF, before calling `fast-uri`. Alternatively, t",
    "evidence": "osv:GHSA-wjr9-j795-jxcr",
    "products": [
      {
        "name": {
          "value": "fast-uri",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.4.8",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "fast-uri",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.1.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "fast-uri",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.2.3",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-wjr9-j795-jxcr",
      "aliases": [
        "CVE-2026-110180",
        "GHSA-wjr9-j795-jxcr"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "2.4.2"
                },
                {
                  "fixed": "2.4.8"
                }
              ]
            }
          ],
          "package": {
            "name": "fast-uri",
            "purl": "pkg:npm/fast-uri",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-wjr9-j795-jxcr/GHSA-wjr9-j795-jxcr.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "3.1.3"
                },
                {
                  "fixed": "3.1.9"
                }
              ]
            }
          ],
          "package": {
            "name": "fast-uri",
            "purl": "pkg:npm/fast-uri",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-wjr9-j795-jxcr/GHSA-wjr9-j795-jxcr.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "4.0.1"
                },
                {
                  "fixed": "4.2.3"
                }
              ]
            }
          ],
          "package": {
            "name": "fast-uri",
            "purl": "pkg:npm/fast-uri",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-wjr9-j795-jxcr/GHSA-wjr9-j795-jxcr.json"
          }
        }
      ],
      "modified": "2026-10-23T21:45:04.892054666Z",
      "provider": "osv",
      "references": [
        "https://github.com/fastify/fast-uri/security/advisories/GHSA-wjr9-j795-jxcr",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-110180",
        "https://github.com/fastify/fast-uri/commit/58c183d0b168ad87f98773266444ce1f6375803a",
        "https://github.com/fastify/fast-uri/commit/ddfc6a51122dfce0365655f04479fc3adb7f6b3c",
        "https://github.com/fastify/fast-uri/commit/f6d46dfeab025d0c440485f4ae29fa4f14707646",
        "https://cna.openjsf.org/security-advisories.html",
        "https://github.com/fastify/fast-uri",
        "https://github.com/fastify/fast-uri/releases/tag/v2.4.8",
        "https://github.com/fastify/fast-uri/releases/tag/v3.1.9",
        "https://github.com/fastify/fast-uri/releases/tag/v4.2.3"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-20",
          "CWE-436"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-20T07:17:08Z",
        "github_reviewed_at": "2026-10-23T21:37:59Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-110180",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 427039,
  "published_at": "2026-10-23T21:37:59+00:00"
}