{"id":"CVE-2026-103651","aliases":["EUVD-2026-90542","GHSA-28mq-63wc-4252"],"status":"published","title":"MISP HOTP Token Replay via Stale Session-Cached Counter Allows Second-Factor Authentication Bypass","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: \u003c2.5.48.","severity":{"version":"4.0","score":7.6,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00196,"percentile":0.09363,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287","CWE-362"],"published":"2026-10-01T07:34:02Z","modified":"2026-10-28T02:30:42Z","products":[{"vendor":"misp","product":"misp"}],"references":[{"url":"https://github.com/MISP/MISP/commit/f34aee2c7","tags":["patch","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-103651","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-28mq-63wc-4252"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103651.json","tags":["advisory"]},{"url":"https://github.com/MISP/MISP","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-103651","title":"MISP HOTP Token Replay via Stale Session-Cached Counter Allows Second-Factor Authentication Bypass","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: \u003c2.5.48.","status":"published","published":"2026-10-01T07:34:02.597Z","modified":"2026-10-01T15:32:08.372Z","cvss":[{"version":"4.0","score":7.6,"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","level":"high","assessor":"cna"}],"cwes":["CWE-362","CWE-287"],"updated_at":"2026-11-02T13:34:37.420074Z"}],"euvd":[{"id":"EUVD-2026-90542","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: \u003c2.5.48.","status":"published","published":"2026-10-01T07:34:02Z","modified":"2026-10-01T15:32:08Z","cvss":[{"version":"4.0","score":7.6,"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","level":"high"}],"updated_at":"2026-11-02T17:27:44.672309Z"}],"ghsa":[{"id":"GHSA-28mq-63wc-4252","title":"MISP contains a vulnerability in its one-time password (OTP) authentication flow that allows...","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: \u003c2.5.48.","status":"published","published":"2026-10-01T09:30:32Z","modified":"2026-10-01T09:30:33Z","cvss":[{"version":"4.0","score":7.6,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T15:12:39.341866Z"}],"nvd":[{"id":"CVE-2026-103651","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: \u003c2.5.48.","status":"published","published":"2026-10-01T08:16:51.02Z","modified":"2026-10-01T16:17:37.313Z","cvss":[{"version":"4.0","score":7.6,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-287","CWE-362"],"updated_at":"2026-11-02T14:12:53.097633Z"}],"osv":[{"id":"CVE-2026-103651","title":"MISP HOTP Token Replay via Stale Session-Cached Counter Allows Second-Factor Authentication Bypass","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: \u003c2.5.48.","status":"published","published":"2026-10-01T07:34:02.597Z","modified":"2026-10-28T02:30:42.689507227Z","cvss":[{"version":"4.0","score":7.6,"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","level":"high"}],"cwes":["CWE-287","CWE-362"],"updated_at":"2026-11-02T15:44:54.236592Z"}]}}