fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery

{
  "id": "3cb496e9c10730009b7178bf3f07f36733f3d4fc50b871745525a3fb98d7789f",
  "url": "https://osv.dev/vulnerability/CVE-2026-72584",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery",
    "summary": "A time-of-check/time-of-use (TOCTOU) race condition in fastschema through v0.15.1 allows an unauthenticated remote attacker to bypass the OTP attempt limit on the account recovery flow, enabling brute-force attacks on 6-digit OTP codes.",
    "evidence": "osv:CVE-2026-72584",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-72584",
      "aliases": [
        "CVE-2026-72584"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/fastschema/fastschema",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "5613d16fe7d144abed0c880abe9f4c49897cf1f5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.15.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.15.1"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.15.1",
            "v0.15.0",
            "v0.14.0",
            "v0.13.1",
            "v0.13.0",
            "v0.12.0",
            "v0.11.1",
            "v0.11.0",
            "v0.10.9",
            "v0.10.8",
            "v0.10.7",
            "v0.10.6",
            "v0.10.5",
            "v0.10.4",
            "v0.10.3",
            "v0.10.2",
            "v0.10.1",
            "v0.10.0",
            "v0.9.0",
            "v0.8.4",
            "v0.7.2",
            "v0.8.3",
            "v0.8.2",
            "v0.8.1",
            "v0.8.0",
            "v0.7.9",
            "v0.7.8",
            "v0.7.7",
            "v0.7.6",
            "v0.7.5",
            "v0.7.4",
            "v0.7.3",
            "v0.7.1",
            "v0.7.0",
            "v0.6.5",
            "v0.6.4",
            "v0.6.3",
            "v0.6.2",
            "v0.6.1",
            "v0.6.0",
            "v0.5.1",
            "v0.5.0",
            "v0.4.0",
            "v0.3.1",
            "v0.3.0",
            "v0.2.0",
            "v0.1.3",
            "v0.1.2",
            "v0.1.1",
            "v0.1.0",
            "v0.0.7",
            "v0.0.6",
            "v0.0.5",
            "v0.0.4",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72584.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.528502697Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72584.json",
        "https://github.com/fastschema/fastschema",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72584",
        "https://github.com/fastschema/fastschema/blob/main/pkg/auth/local.go"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-367"
        ],
        "cna_assigner": "TuranSec",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72584.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72584",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 512519,
  "published_at": "2026-08-10T10:41:27.492+00:00"
}