{"cve":"CVE-2026-103651","nvd":{"published":"2026-10-01T08:16:51.020","modified":"2026-10-01T16:17:37.313","status":"Deferred","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.","cvss_v4":{"vector":"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","score":7.6},"cvss_v3":null,"cwes":["CWE-287","CWE-362"],"references":["https://github.com/MISP/MISP/commit/f34aee2c7"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:57:46.668721662+00:00"},"epss":{"cve":"CVE-2026-103651","score":0.00196,"percentile":0.0916,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}