CVE-2026-53997

Received Received - Intake

Authentication Bypass in Netherman Portal del Hermano

Publication date: 2026-10-12

Last updated on: 2026-10-12

Assigner: VulnCheck

Description

Netherman Portal del Hermano (portaldelhermano.es) before 2026-10-06 contains a broken authentication vulnerability in its password-recovery flow at the POST /password/create-access and POST /password/email endpoints, allowing unauthenticated attackers to take over any member account across all tenants by exploiting the lack of rate limiting and distinct error messages that act as oracles for each of the four identity-verification factors (DNI, date of birth, phone number, last four IBAN digits). Attackers can confirm the DNI via the oracle, brute-force the date of birth and IBAN digits, obtain the phone number through open-source intelligence, then submit an attacker-controlled email field so the password reset link is delivered to them, enabling full account takeover including profile data, full IBAN, and fiscal documents.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-12

Last Modified

2026-10-12

Generated

2026-10-13

AI Q&A

2026-10-13

EPSS Evaluated

N/A

NVD

CVE-2026-53997

Affected Vendors & Products

Vendor	Product	Version / Range
NetHerman	Portal	del Hermano (portaldelhermano.es) 0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-307	The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
CWE-640	The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.

Attack-Flow Graph

Executive Summary

This vulnerability is a broken authentication flaw in Netherman Portal del Hermano (portaldelhermano.es) before 2026-10-06. It exists in the password-recovery process at POST /password/create-access and POST /password/email endpoints. Unauthenticated attackers can exploit it to take over any member account across all tenants by bypassing identity verification factors like DNI, date of birth, phone number, and IBAN digits due to lack of rate limiting and distinct error messages that act as oracles.

Detection Guidance

This vulnerability is specific to Netherman Portal del Hermano and cannot be detected via standard network or system commands. The issue lies in the web application's password-recovery endpoints (/password/create-access and /password/email). Monitor for unusual activity such as repeated password reset requests or successful account takeovers.

Impact Analysis

If you are a user of Netherman Portal del Hermano, attackers could gain full control of your account, including access to profile data, full IBAN, and fiscal documents. This could lead to financial fraud, identity theft, or unauthorized access to sensitive personal information.

Compliance Impact

This vulnerability likely violates GDPR due to unauthorized access to personal data and insufficient security measures. It may also breach HIPAA if protected health information is exposed. Organizations using this system could face legal penalties, regulatory fines, and reputational damage for failing to protect user data adequately.

Mitigation Strategies

Immediately update Netherman Portal del Hermano to the latest version (after 2026-10-06). Implement rate limiting on password-recovery endpoints. Disable or modify error messages to avoid oracle behavior. Ensure strong multi-factor authentication is enforced.

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