{"id":"CVE-2026-103651","published":"2026-10-01T08:16:51.020","lastModified":"2026-10-01T16:17:37.313","description":"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: <2.5.48.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-287","CWE-362"],"vendors":[],"products":[],"references":[{"url":"https://github.com/MISP/MISP/commit/f34aee2c7","tags":[]}],"exploitRefs":[{"url":"https://github.com/MISP/MISP/commit/f34aee2c7","tags":[]}],"hasPoc":true,"ai":null}