openssl_encrypt before 1.4.6 KDF Bypass via Sequential-XOR

{
  "id": "5caaf971bc4ca415fd6c85c2808431368a3ae8136763b891f0ed13b1295a9b0d",
  "url": "https://osv.dev/vulnerability/CVE-2026-74871",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "openssl_encrypt before 1.4.6 KDF Bypass via Sequential-XOR",
    "summary": "openssl_encrypt versions before 1.4.6 contain a key derivation flaw in sequential XOR composition mode where the last stage cancels out during key generation. When configured with a single KDF and no prior hashing stage, attackers can bypass memory-hard key derivation and perform offline password cracking at SHA-256 speed instead of the configured KDF cost.",
    "evidence": "osv:CVE-2026-74871",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-74871",
      "aliases": [
        "CVE-2026-74871",
        "GHSA-vxf9-vwp6-2w43",
        "PYSEC-2026-3976"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/jahlives/openssl_encrypt",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "805ee093ec87b8426235df9077ef8d6bd41f15cb"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.4.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:jahlives:openssl_encrypt:*:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.4.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.5",
            "v1.4.4",
            "v1.4.2",
            "v1.4.1rc2",
            "v1.4.1rc1",
            "v1.4.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74871.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.087715898Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74871.json",
        "https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-vxf9-vwp6-2w43",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-74871",
        "https://www.vulncheck.com/advisories/openssl-encrypt-before-kdf-bypass-via-sequential-xor"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-916"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74871.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-74871",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507610,
  "published_at": "2026-08-17T11:04:40.877+00:00"
}