openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost

{
  "id": "7bfb263b7703525324db4e97c7654be4e1e913cadb87151c906bfe09ec89f03d",
  "url": "https://osv.dev/vulnerability/CVE-2026-81699",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost",
    "summary": "openssl_encrypt versions before 1.4.9 fail to properly validate key derivation function costs in crafted files, allowing attackers to trigger unbounded memory and CPU exhaustion during pre-authentication processing. Attackers can supply malicious files with excessive KDF parameters to exhaust system resources and crash or wedge the process before password verification occurs.",
    "evidence": "osv:CVE-2026-81699",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-81699",
      "aliases": [
        "CVE-2026-81699",
        "GHSA-phmr-p567-q5g6",
        "PYSEC-2026-3961"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/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": "39b0a010cae90520f74b7194f61fedd43af04ef8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.4.9"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:jahlives:openssl_encrypt:*:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.4.9"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.7",
            "v1.4.6",
            "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-2026-81699.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.765762361Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81699.json",
        "https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-phmr-p567-q5g6",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-81699",
        "https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-unbounded-kdf-cost"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81699.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-81699",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517988,
  "published_at": "2026-08-27T14:51:03.419+00:00"
}