Security advisory

{
  "id": "dffe273b913eed81440519fd6406a3f385fe579fbdc7ee60c9d465e911e56472",
  "url": "https://osv.dev/vulnerability/CVE-2020-28042",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-28042",
    "summary": "ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has a custom ValidateToken function that establishes a valid minimum length for a signature.",
    "evidence": "osv:CVE-2020-28042",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-28042",
      "aliases": [
        "CVE-2020-28042",
        "GHSA-v5rv-hpxg-8x49"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/servicestack/servicestack",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "b3f3f3f3df9eae8f665aa3b02ce707c4902c62dc"
                },
                {
                  "fixed": "540d4060e877a03ae95343c1a8560a26768585ee"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:servicestack:servicestack:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.9.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "540d4060e877a03ae95343c1a8560a26768585ee"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v5.9",
            "v5.8",
            "v5.7",
            "v5.6",
            "v5.5",
            "v5.4",
            "v5.2.0",
            "v5.1.0",
            "v5.0.2",
            "v5",
            "v4.5.12",
            "v4.5.6",
            "v4.5.8",
            "v4.5.4",
            "v4.5.2",
            "v4.5.0",
            "v4.0.62",
            "v4.0.60",
            "v4.0.58",
            "v4.0.56",
            "v4.0.54",
            "v4.0.52",
            "v4.0.50",
            "v4.0.48",
            "v4.0.46",
            "v4.0.44",
            "v4.0.42",
            "v4.0.40",
            "v4.0.38",
            "v4.0.36",
            "v4.0.35",
            "v4.0.34",
            "v4.0.33",
            "v4.0.32",
            "v4.0.31",
            "v4.0.30",
            "v4.0.24",
            "v4.0.23",
            "v4.0.22",
            "v4.0.21",
            "v4.0.20",
            "v4.0.19",
            "v4.0.18",
            "v4.0.17",
            "v4.0.10-sync",
            "v3-snapshot"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-28042.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:19.282194193Z",
      "provider": "osv",
      "references": [
        "https://forums.servicestack.net/t/servicestack-v5-9-2-released/8850",
        "https://github.com/ServiceStack/ServiceStack/commit/540d4060e877a03ae95343c1a8560a26768585ee",
        "https://www.shielder.it/advisories/servicestack-jwt-signature-verification-bypass/",
        "https://www.shielder.it/blog/2020/11/re-discovering-a-jwt-authentication-bypass-in-servicestack/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-28042",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385036,
  "published_at": "2020-11-02T21:15:31.32+00:00"
}