{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "53fccd93413a8d7f07d6d8999681f27b75cffa3f"
            }
          ],
          "repo": "https://github.com/pyca/cryptography",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-g6cj-pr64-35w5"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-208",
      "CWE-209"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69247.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "44.0.0"
          },
          {
            "fixed": "50.0.0"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An application that decrypts attacker-supplied EnvelopedData and reflects the outcome gives the attacker a Bleichenbacher oracle against the content-encryption key. Decryption ran as RSA PKCS#1 v1.5 decrypt of encryptedKey, build an AES cipher from the result, then AES-CBC decrypt and PKCS#7 unpad. Invalid RSA padding, a valid padding with a bad key length, a correct length with a wrong key, and the real key each failed or succeeded differently. Case 1 is reachable only where the linked library lacks implicit rejection: OpenSSL 3.0 and 3.1, LibreSSL, and BoringSSL. Exploitation requires a service that auto-decrypts untrusted EnvelopedData matching the victim certificate and answers adaptively at high volume, such as an S/MIME gateway or mail filter. This issue is fixed in 50.0.0.",
  "id": "CVE-2026-69247",
  "modified": "2026-08-05T03:30:10.149683632Z",
  "published": "2026-08-03T21:16:32.047Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69247.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-g6cj-pr64-35w5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-69247"
    },
    {
      "type": "FIX",
      "url": "https://github.com/pyca/cryptography/commit/53fccd93413a8d7f07d6d8999681f27b75cffa3f"
    },
    {
      "type": "FIX",
      "url": "https://github.com/pyca/cryptography/pull/15369"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing"
}