CVE-2026-103651
Deferred
Deferred - Pending Action
HOTP Replay Vulnerability in MISP
Vulnerability report for CVE-2026-103651, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-01
Last updated on: 2026-10-01
Assigner: CIRCL
Description
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.
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 Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| misp | misp | to 2.5.48 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-362 | The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. |
| CWE-287 | When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. |
