Security advisory

{
  "id": "6ebb17dd031fc3716783660668d7a252c07b585eab72918a934bacf9af779eed",
  "url": "https://osv.dev/vulnerability/CVE-2018-10903",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2018-10903",
    "summary": "A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.",
    "evidence": "osv:CVE-2018-10903",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2018-10903",
      "aliases": [
        "CVE-2018-10903",
        "GHSA-fcf9-3qw3-gxmj",
        "PYSEC-2018-52"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pyca/cryptography",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0a846e294806478770469219a26cd49dcb5502d7"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:cryptography:python-cryptography:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.9.0"
                      },
                      {
                        "fixed": "2.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.2",
            "2.1",
            "2.0",
            "1.9",
            "1.8",
            "1.7",
            "1.6",
            "1.5",
            "1.4",
            "1.3",
            "1.2",
            "1.1",
            "1.0",
            "0.9",
            "0.8",
            "0.7",
            "0.6",
            "0.5.1",
            "0.5",
            "0.4",
            "0.3",
            "0.2",
            "0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-10903.json"
          }
        }
      ],
      "modified": "2026-10-20T10:50:16.309366168Z",
      "provider": "osv",
      "references": [
        "https://access.redhat.com/errata/RHSA-2018:3600",
        "https://usn.ubuntu.com/3720-1/",
        "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903",
        "https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*"
            ],
            "vendor_product": "canonical:ubuntu_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "18.04"
                  },
                  {
                    "last_affected": "18.04"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:*"
            ],
            "vendor_product": "redhat:openstack",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "13"
                  },
                  {
                    "last_affected": "13"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2018-10903",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 381472,
  "published_at": "2018-07-30T16:29:00.283+00:00"
}