{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "5.7.4"
              },
              {
                "last_affected": "5.9.1"
              },
              {
                "fixed": "5.9.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "bdd62314f00fca0e216bf8c963c8eeff6327e0cb"
            },
            {
              "fixed": "ac01707f552c611fbd135cc723b2682b3e7f80f2"
            }
          ],
          "repo": "https://github.com/wolfssl/wolfssl",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "wolfSSL",
    "cwe_ids": [
      "CWE-295"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6091.json"
  },
  "details": "Partial-chain certificate verification may accept chains that terminate at a peer-supplied, untrusted intermediate certificate rather than a trusted anchor. An attacker could present a chain that ends at an intermediate they control and have it accepted as valid. This affects the OpenSSL compatibility certificate-path-building path (wolfSSL_X509_verify_cert / X509_STORE, OPENSSL_EXTRA) when the X509_V_FLAG_PARTIAL_CHAIN verify flag is enabled.",
  "id": "CVE-2026-6091",
  "modified": "2026-07-16T03:31:15.801537755Z",
  "published": "2026-06-25T16:46:12.599Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.wolfssl.com/docs/security-vulnerabilities/"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6091.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6091"
    },
    {
      "type": "FIX",
      "url": "https://github.com/wolfSSL/wolfssl/pull/10170"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/wolfSSL/wolfssl"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Partial-chain verification accepts untrusted intermediate as trust anchor"
}