{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.5.48"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f34aee2c7"
            }
          ],
          "repo": "https://github.com/misp/misp",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "CIRCL",
    "cwe_ids": [
      "CWE-287",
      "CWE-362"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103651.json"
  },
  "details": "MISP contains a vulnerability in its one-time password (OTP) authentication flow that allows replay of a consumed HOTP (paper) token and rewinding of the token counter.\n\nThe HOTP verification logic compared the submitted token against a counter value that was cached in the user's session at the time the password was entered, rather than against the authoritative counter stored in the database. Because the session-cached counter is not updated after a token is successfully consumed, an attacker who holds a valid session (password already submitted) can reuse a previously burned HOTP token. The stale cached counter still matches the replayed token, granting a second successful authentication and effectively rewinding the counter state.\n\nPreconditions:\n\n- The target user has HOTP (paper token) second-factor authentication enabled.\n\n- The attacker possesses a valid session in which the password step has already been completed (the OTP step is pending).\n\n- The attacker has access to at least one HOTP token value (e.g., a paper token list).\n\nSecurity impact:\n\n- Bypass of the second authentication factor, allowing unauthorized access to a user's MISP account.\n\n- Corruption of the HOTP counter state, potentially invalidating subsequent legitimate tokens or enabling further replays.\n\nAffected versions: \u003c2.5.48.",
  "id": "CVE-2026-103651",
  "modified": "2026-10-04T02:30:38.987900622Z",
  "published": "2026-10-01T07:34:02.597Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103651.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103651"
    },
    {
      "type": "FIX",
      "url": "https://github.com/MISP/MISP/commit/f34aee2c7"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/MISP/MISP"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MISP HOTP Token Replay via Stale Session-Cached Counter Allows Second-Factor Authentication Bypass"
}