python-cryptography — security advisory

{
  "id": "8510cc02040efa2d1509d70181a888360434fc853199eefcb50a0334351d05fe",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-69247",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-69247",
    "summary": "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.",
    "evidence": "osv:DEBIAN-CVE-2026-69247",
    "products": [
      {
        "name": {
          "value": "python-cryptography",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "49.0.0-2",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "43.0.0-3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "44.0.2-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "44.0.2-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "45.0.6-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "45.0.6-1~exp1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "45.0.7-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.1-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.1-1~exp1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.5-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.5-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.6-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "46.0.7-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "47.0.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "49.0.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "49.0.0-1~exp1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2026-69247",
      "aliases": [
        "DEBIAN-CVE-2026-69247"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "49.0.0-2"
                }
              ]
            }
          ],
          "package": {
            "name": "python-cryptography",
            "purl": "pkg:deb/debian/python-cryptography?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "versions": [
            "43.0.0-3",
            "44.0.2-1",
            "44.0.2-2",
            "45.0.6-1",
            "45.0.6-1~exp1",
            "45.0.7-1",
            "46.0.1-1",
            "46.0.1-1~exp1",
            "46.0.5-1",
            "46.0.5-2",
            "46.0.6-1",
            "46.0.7-1",
            "47.0.0-1",
            "49.0.0-1",
            "49.0.0-1~exp1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-69247.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-24T09:47:35.704009336Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-69247"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-69247"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-69247",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 429042,
  "published_at": "2026-08-03T22:16:52.38+00:00"
}