{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.0.2.8"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "90ff5b13b13b5673c372e188f482d8c172e6ab86"
            },
            {
              "fixed": "896a6bdd527e1cbf351ebbdd2f513296b49a7f95"
            }
          ],
          "repo": "https://github.com/jetperch/pymonocypher",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8f95-v3jq-cj86"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-122",
      "CWE-1284",
      "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53720.json"
  },
  "details": "pymonocypher uses cython to wrap the Monocypher C library. Prior to version 4.0.2.8, the argon2i_32 implementation does not check the nb_blocks size. If the caller does not provide a sufficiently large buffer based on the API contract, then argon2i_32 will write past the end of the buffer and possibly corrupt the heap. This issue has been patched in version 4.0.2.8.",
  "id": "CVE-2026-53720",
  "modified": "2026-09-05T03:30:51.044003022Z",
  "published": "2026-09-03T15:30:06.690Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jetperch/pymonocypher/releases/tag/v4.0.2.8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53720.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jetperch/pymonocypher/security/advisories/GHSA-8f95-v3jq-cj86"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53720"
    },
    {
      "type": "FIX",
      "url": "https://github.com/jetperch/pymonocypher/commit/90ff5b13b13b5673c372e188f482d8c172e6ab86"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small"
}