{"id":"CVE-2026-103651","title":"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 …","summary":"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 …","severity":"high","cvss":7.6,"cvssVector":"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","cwe":["CWE-287","CWE-362"],"vendor":"MISP","product":"MISP","affected":["MISP < 2.5.48"],"published":"2026-10-01","updated":"2026-10-01","sourceUpdated":"2026-10-01T08:16:51.143","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103651","references":[{"url":"https://github.com/MISP/MISP/commit/f34aee2c7","label":"5a6e4751-2f3f-4070-9419-94fb35b644e8"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-10-01T08:40:11.738Z","slug":"CVE-2026-103651","body":"## Overview\n\nMISP 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}