---
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.


  The 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.


  The 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'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.