Vikunja: Permissive Cross-domain Security Policy trusts every localhost origin which should not be trusted

{
  "id": "7fe810f7ebf6b98bb3c25a12887b3df4357e25612f1b80ba7e071cad1b61be6d",
  "url": "https://osv.dev/vulnerability/GHSA-m687-p538-r5hp",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vikunja: Permissive Cross-domain Security Policy trusts every localhost origin which should not be trusted",
    "summary": "## Summary Vikunja ships with `cors.origins` defaulting to `http://127.0.0.1:*` and `http://localhost:*`, and sends `Access-Control-Allow-Credentials: true`, so a page served from any port on the user's own machine may make credentialed cross-origin requests to the API and read the responses. The mandatory `service.publicurl` is appended to that default list rather than replacing it, so a fully configured production deployment still trusts every localhost origin. Combined with the token refresh endpoint, which authenticates with the `vikunja_refresh_token` cookie and returns a bearer JWT in the response body, one `fetch()` from such a page yields a working access token for whoever is logged in, and from there the whole account. ## Vulnerability Details `cors.enable` defaults to true and `cors.origins` defaults to the two localhost wildcards: https://github.com/go-vikunja/vikunja/blob/a881ac39eecd07575a5aede8e74727c28d5fd578/pkg/config/config.go#L495-L497 The middleware is registered with `AllowCredentials: true` and an `UnsafeAllowOriginFunc` that implements the port wildcard through `matchCORSOrigin`, since Echo v5 will not accept a wildcard port itself: https://github.com/go-vikunja/vikunja/blob/a881ac39eecd07575a5aede8e74727c28d5fd578/pkg/routes/routes.go#L263-L281 The detail that turns a development convenience into a production exposure is the last line of configuration handling. Enabling CORS without a public URL is a fatal error, so every deployment sets one, and that ",
    "evidence": "osv:GHSA-m687-p538-r5hp",
    "products": [
      {
        "name": {
          "value": "code.vikunja.io/api",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-m687-p538-r5hp",
      "aliases": [
        "CVE-2026-111922",
        "GHSA-m687-p538-r5hp",
        "GO-2026-6739"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "2.2.0"
                },
                {
                  "last_affected": "2.6.0"
                }
              ]
            }
          ],
          "package": {
            "name": "code.vikunja.io/api",
            "purl": "pkg:golang/code.vikunja.io/api",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-m687-p538-r5hp/GHSA-m687-p538-r5hp.json"
          }
        }
      ],
      "modified": "2026-10-19T21:40:54.835844206Z",
      "provider": "osv",
      "references": [
        "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m687-p538-r5hp",
        "https://github.com/go-vikunja/vikunja"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-942"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-09T20:57:50Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111922",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 376752,
  "published_at": "2026-10-09T20:57:50+00:00"
}