Crypt::DSA versions before 1.21 for Perl reused the nonce across signatures, leading to private-key recovery

{
  "id": "137a9fb393ad45d56a9a9477d9d184239fb5ec575c0355c1026cde380f247c1d",
  "url": "https://osv.dev/vulnerability/CVE-2026-12205",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Crypt::DSA versions before 1.21 for Perl reused the nonce across signatures, leading to private-key recovery",
    "summary": "Crypt::DSA versions before 1.21 for Perl reused the nonce across signatures, leading to private-key recovery. Crypt::DSA::sign caches the per-signature nonce material in the Key object without ever clearing it. The first sign() on a Key object picks a nonce, and every later sign() on that same object reuses it, producing an identical \"r\". Keys used to sign more than once with an affected version should be considered compromised.",
    "evidence": "osv:CVE-2026-12205",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-12205",
      "aliases": [
        "CVE-2026-12205"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/perl-crypt-openpgp/crypt-dsa",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ff96123c051e9582c8645cd79bdc061ee2f31c55"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.21"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.20",
            "1.19",
            "1.18",
            "1.17"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12205.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.769879375Z",
      "provider": "osv",
      "references": [
        "https://cpan.org/modules",
        "https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.20/source/lib/Crypt/DSA.pm#L47",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12205.json",
        "https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/changes",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-12205",
        "https://github.com/perl-Crypt-OpenPGP/Crypt-DSA"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-323"
        ],
        "cna_assigner": "CPANSec",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12205.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-12205",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489244,
  "published_at": "2026-06-15T21:57:18.317+00:00"
}