SvelteKit: URL redirection to untrusted site via enhanced form submission

{
  "id": "f0fd182fb3a3530e39665578cb452f8945e5c6d0a18b929eeea24edd1585093b",
  "url": "https://osv.dev/vulnerability/GHSA-pfhg-q3qv-9q6r",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SvelteKit: URL redirection to untrusted site via enhanced form submission",
    "summary": "### Impact Applications using enhanced form actions (`use:enhance`) on routes that accept paths beginning with `//`, such as catch-all routes, may be vulnerable to an open redirect. ### Patches A fix has been prepared for `@sveltejs/kit` 3.0.0. Users should upgrade to 3.0.0 or later. The fix preserves leading double slashes in action paths without generating protocol-relative URLs, restricts non-redirect action navigation to the current origin, and includes the origin when comparing action locations with the current page. ### Workarounds Reject requests whose parsed URL pathname begins with `//` before route resolution, for example in a reverse proxy or a SvelteKit `handle` hook. Alternatively, disable navigation for non-redirect enhanced form results by supplying a custom submission callback: ```svelte ({ update }) => update({ navigate: false })}> ``` This applies non-redirect results to the current page instead of navigating to the action location.",
    "evidence": "osv:GHSA-pfhg-q3qv-9q6r",
    "products": [
      {
        "name": {
          "value": "@sveltejs/kit",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.0.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "low",
    "structured": {
      "id": "GHSA-pfhg-q3qv-9q6r",
      "aliases": [
        "CVE-2026-114060",
        "GHSA-pfhg-q3qv-9q6r"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N"
        },
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.0.0"
                }
              ]
            }
          ],
          "package": {
            "name": "@sveltejs/kit",
            "purl": "pkg:npm/%40sveltejs/kit",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-pfhg-q3qv-9q6r/GHSA-pfhg-q3qv-9q6r.json"
          }
        }
      ],
      "modified": "2026-10-23T21:15:03.741776060Z",
      "provider": "osv",
      "references": [
        "https://github.com/sveltejs/kit/security/advisories/GHSA-pfhg-q3qv-9q6r",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-114060",
        "https://github.com/sveltejs/kit/commit/91aae3547c6cd2935d79c09a53e27c740100000a",
        "https://github.com/sveltejs/kit",
        "https://github.com/sveltejs/kit/releases/tag/@sveltejs/kit@3.0.0",
        "https://www.vulncheck.com/advisories/sveltekit-before-3.0.0-open-redirect-via-enhanced-form-actions"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-601"
        ],
        "severity": "LOW",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-23T20:58:24Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-114060",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 427035,
  "published_at": "2026-10-23T20:58:24+00:00"
}