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.
The 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.
Preconditions:
- The target user has HOTP (paper token) second-factor authentication enabled.
- The attacker possesses a valid session in which the password step has already been completed (the OTP step is pending).
- The attacker has access to at least one HOTP token value (e.g., a paper token list).
Security impact:
- Bypass of the second authentication factor, allowing unauthorized access to a user's MISP account.
- Corruption of the HOTP counter state, potentially invalidating subsequent legitimate tokens or enabling further replays.
Affected versions: <2.5.48.
CVSS
No CVSS.
References
| Link | Resource |
|---|---|
| https://github.com/MISP/MISP/commit/f34aee2c7 |
Configurations
No configuration.
History
01 Oct 2026, 08:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-10-01 08:16
Updated : 2026-10-01 16:17
NVD link : CVE-2026-103651
Mitre link : CVE-2026-103651
CVE.ORG link : CVE-2026-103651
JSON object : View
Products Affected
No product.