Authlib library contains a signature‑verification bypass vulnerability

{
  "id": "02461efbf9428f28ba1ba868d7a52381163fc239f3096b1c183bef1c730218fd",
  "url": "https://osv.dev/vulnerability/CVE-2026-96760",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Authlib library contains a signature‑verification bypass vulnerability",
    "summary": "Authlib (v1.7.2 and below) contains a signature verification bypass vulnerability. The JsonWebSignature.deserialize_json() method accepts a JSON Serialization JWS object and returns the payload as successfully verified without checking for a signature and without requiring a cryptographic key.",
    "evidence": "osv:CVE-2026-96760",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-96760",
      "aliases": [
        "CVE-2026-96760",
        "GHSA-6v38-4h7w-rj9h"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/authlib/authlib",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a0b76fac3fa114d7759af2010546bfc332364b63"
                },
                {
                  "last_affected": "a0b76fac3fa114d7759af2010546bfc332364b63"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.7.2"
                      },
                      {
                        "last_affected": "1.7.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.7.2"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.7.2",
            "v1.7.2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-96760.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.067589450Z",
      "provider": "osv",
      "references": [
        "https://kb.cert.org/vuls/id/762428",
        "https://www.kb.cert.org/vuls/id/762428",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/96xxx/CVE-2026-96760.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-96760",
        "https://github.com/authlib/authlib"
      ],
      "provider_metadata": {
        "cna_assigner": "certcc",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/96xxx/CVE-2026-96760.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-96760",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 510011,
  "published_at": "2026-09-28T19:37:58.973+00:00"
}