MISP up to 2.5.44 Email OTP email_otp excessive authentication

Summaryinfo

A vulnerability categorized as problematic has been discovered in MISP up to 2.5.44. Affected by this issue is the function email_otp of the component Email OTP. Executing a manipulation can lead to excessive authentication. This vulnerability is handled as CVE-2026-85237. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic was found in MISP up to 2.5.44. This vulnerability affects the function email_otp of the component Email OTP. The manipulation with an unknown input leads to a excessive authentication vulnerability. The CWE definition for the vulnerability is CWE-307. The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks. As an impact it is known to affect confidentiality. CVE summarizes:

A vulnerability in MISP's email-based one-time password (OTP) authentication flow allowed an attacker to perform an unrestricted number of OTP verification attempts. The email_otp() endpoint did not apply brute-force protection when validating submitted OTP values. An attacker who had reached the OTP verification stage, for example after successfully providing a user's primary authentication credentials, could repeatedly submit candidate OTP values while the same OTP remained valid. This significantly increased the feasibility of guessing the OTP and bypassing the additional authentication factor, potentially resulting in unauthorized access to the affected user's account. The issue was exacerbated by the fact that the OTP is associated with the user rather than with an individual pending login session, allowing multiple concurrent sessions to attempt guesses against the same valid OTP. The patch integrates the existing MISP brute-force protection mechanism into the email OTP flow. Failed OTP attempts are now counted against the user, further attempts are rejected once the configured threshold is reached, and the active OTP is invalidated when the attempt budget is exhausted. Blocklisted users are also prevented from requesting the generation of a fresh OTP. In addition, OTP comparison now uses hash_equals() and validates that the submitted value is a string.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-85237 since 09/03/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1110.001.

Upgrading to version 2.5.45 eliminates this vulnerability. Applying the patch 8658062ea is able to eliminate this problem.

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Productinfo

Name

• MISP

Version

• 2.5.0
• 2.5.1
• 2.5.2
• 2.5.3
• 2.5.4
• 2.5.5
• 2.5.6
• 2.5.7
• 2.5.8
• 2.5.9
• 2.5.10
• 2.5.11
• 2.5.12
• 2.5.13
• 2.5.14
• 2.5.15
• 2.5.16
• 2.5.17
• 2.5.18
• 2.5.19
• 2.5.20
• 2.5.21
• 2.5.22
• 2.5.23
• 2.5.24
• 2.5.25
• 2.5.26
• 2.5.27
• 2.5.28
• 2.5.29
• 2.5.30
• 2.5.31
• 2.5.32
• 2.5.33
• 2.5.34
• 2.5.35
• 2.5.36
• 2.5.37
• 2.5.38
• 2.5.39
• 2.5.40
• 2.5.41
• 2.5.42
• 2.5.43
• 2.5.44

License

• open-source

Website

• Product: https://github.com/MISP/MISP/

CPE 2.3info

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