Apache CXF: The authorization code hash (c_hash) is not enforced for the hybrid OIDC flow

{
  "id": "00d11555ab775b59bbae840efcd4476fba0114cb421399e6f2b91f13b8bdd0c0",
  "url": "https://osv.dev/vulnerability/CVE-2026-57817",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Apache CXF: The authorization code hash (c_hash) is not enforced for the hybrid OIDC flow",
    "summary": "The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the `c_hash` parameter when operating in the Hybrid Flow. If an Apache CXF RP is integrated with a non-compliant or misconfigured Identity Provider (IdP) that omits the `c_hash`, the RP becomes vulnerable to Authorization Code Substitution/Injection attacks. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.",
    "evidence": "osv:CVE-2026-57817",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-57817",
      "aliases": [
        "CVE-2026-57817"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/apache/cxf",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "16d606b3c4d5c7d271fd3b488c60a208586acb3f"
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                {
                  "introduced": "02310e95fe74c0c031f540f3284e4a9bd856ced2"
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                {
                  "fixed": "8797a177ec23e9c578c78a630c154ad27d9bbe8d"
                },
                {
                  "introduced": "04ccbfd709eef8f4af53d6237514fbe9db7ea81f"
                },
                {
                  "fixed": "33259395b45b4ff69b8df6a153630721fdd489fa"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:apache:cxf:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.6.12"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:cxf:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.0.0"
                      },
                      {
                        "fixed": "4.1.8"
                      }
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                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:cxf:*:*:*:*:*:*:*:*",
                    "range": [
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                        "introduced": "4.2.0"
                      },
                      {
                        "fixed": "4.2.3"
                      }
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                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "cxf-4.1.7",
            "cxf-4.2.2",
            "cxf-3.6.11",
            "cxf-4.1.6",
            "cxf-4.2.1",
            "cxf-3.6.10",
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            "cxf-4.2.0",
            "cxf-3.6.9",
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            "cxf-3.6.8",
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            "cxf-3.6.7",
            "cxf-4.1.2",
            "cxf-3.6.6",
            "cxf-4.1.1",
            "cxf-4.1.0",
            "cxf-3.6.5",
            "cxf-3.6.4",
            "cxf-3.6.3",
            "cxf-4.0.4",
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            "cxf-4.0.2",
            "cxf-3.6.1",
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            "cxf-3.5.0",
            "cxf-3.4.1",
            "cxf-3.4.0",
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            "cxf-3.3.1",
            "cxf-3.3.0",
            "cxf-3.2.5",
            "cxf-3.2.4",
            "cxf-3.2.3",
            "cxf-3.2.2",
            "cxf-3.2.1",
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            "cxf-3.1.3",
            "cxf-3.1.2",
            "cxf-3.1.1",
            "cxf-3.1.0",
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            "cxf-2.7.2",
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            "cxf-2.6.0",
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            "cxf-2.4.0",
            "cxf-2.3.0",
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            "cxf-2.2.1",
            "cxf-2.2",
            "cxf-2.1.2",
            "cxf-2.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-57817.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.132278615Z",
      "provider": "osv",
      "references": [
        "https://repo.maven.apache.org/maven2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57817.json",
        "https://lists.apache.org/thread/pj63c3pf7kkp1xhr53do704fwj3t3htn",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-57817"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-20"
        ],
        "cna_assigner": "apache",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "4.2.0"
                  },
                  {
                    "fixed": "4.2.3"
                  },
                  {
                    "introduced": "4.0.0"
                  },
                  {
                    "fixed": "4.1.8"
                  },
                  {
                    "fixed": "3.6.12"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57817.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-57817",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513350,
  "published_at": "2026-08-06T10:24:05.877+00:00"
}