{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:leancrypto:leancrypto:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.7.1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "e7fa8c87a46c5787174c18fac385aa08eecdedd1"
            },
            {
              "fixed": "5cdcbe12bd6c3d6e87e969972a580b44a74c3a6a"
            }
          ],
          "repo": "https://github.com/smuellerdd/leancrypto",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-636g-jxv4-v4gr"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-681"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34610.json"
  },
  "details": "The leancrypto library is a cryptographic library that exclusively contains only PQC-resistant cryptographic algorithms. Prior to version 1.7.1, lc_x509_extract_name_segment() casts size_t vlen to uint8_t when storing the Common Name (CN) length. An attacker who crafts a certificate with CN = victim's CN + 256 bytes padding gets cn_size = (uint8_t)(256 + N) = N, where N is the victim's CN length. The first N bytes of the attacker's CN are the victim's identity. After parsing, the attacker's certificate has an identical CN to the victim's — enabling identity impersonation in PKCS#7 verification, certificate chain matching, and code signing. This issue has been patched in version 1.7.1.",
  "id": "CVE-2026-34610",
  "modified": "2026-07-15T01:49:16.555496628Z",
  "published": "2026-04-02T17:54:53.250Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/smuellerDD/leancrypto/releases/tag/v1.7.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34610.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/smuellerDD/leancrypto/security/advisories/GHSA-636g-jxv4-v4gr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34610"
    },
    {
      "type": "FIX",
      "url": "https://github.com/smuellerDD/leancrypto/commit/5cdcbe12bd6c3d6e87e969972a580b44a74c3a6a"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "leancrypto: Integer truncation in X.509 name parser enables certificate identity impersonation"
}