CVE-2026-93556 Overview
CVE-2026-93556 is an Insecure Direct Object Reference (IDOR) vulnerability in a password recovery endpoint. The affected /password/guardarClau/recover endpoint accepts a usuariId parameter that identifies the target account. The recovery JSON Web Token (JWT) is not validated against the user identifier supplied in the request. An unauthenticated attacker can manipulate usuariId to reset the password of any account, including administrator accounts. Successful exploitation results in full account takeover. The weakness is tracked as CWE-639: Authorization Bypass Through User-Controlled Key.
Critical Impact
An unauthenticated attacker can reset passwords for arbitrary accounts, including administrative users, leading to complete account takeover.
Affected Products
- Application exposing the /password/guardarClau/recover endpoint (vendor and product details not published in the NVD entry)
Discovery Timeline
- 2026-09-22 - CVE-2026-93556 published to the National Vulnerability Database (NVD)
- 2026-09-22 - Last updated in NVD database
Technical Details for CVE-2026-93556
Vulnerability Analysis
The vulnerability resides in the password recovery workflow. The /password/guardarClau/recover endpoint accepts a usuariId parameter that names the account whose password will be changed. The endpoint also expects a recovery JWT, which is issued when a legitimate user initiates the password reset flow.
The server fails to verify that the account identifier bound to the JWT matches the usuariId submitted in the request. As a result, a valid recovery token issued for one account can be reused to set the password of any other account. The flaw is classified as [CWE-639], an authorization bypass through a user-controlled key.
Root Cause
The root cause is missing object-level authorization. The application trusts the client-supplied usuariId value instead of deriving the target account from the authenticated subject encoded in the JWT sub or equivalent claim. Because both the token and the target identifier are user-controlled inputs, the server must cross-validate them before mutating credentials.
Attack Vector
The attack is remote and unauthenticated. An attacker requests a legitimate password reset for an account they control, obtaining a valid recovery JWT. The attacker then submits that JWT to /password/guardarClau/recover while setting usuariId to the numeric identifier of a target account, such as an administrator. The server accepts the request and overwrites the target account's password with an attacker-chosen value. The attacker authenticates with the new credentials and inherits the target account's privileges. For additional context, see the Incibe Security Notice on IDOR.
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Stop Identity AttacksDetection Methods for CVE-2026-93556
Indicators of Compromise
- Requests to /password/guardarClau/recover where the usuariId parameter does not match the account bound to the presented JWT.
- Password changes on privileged accounts that are not preceded by an authenticated session or a matching password reset initiation event.
- Multiple password reset completions from the same source Internet Protocol (IP) address targeting different usuariId values.
Detection Strategies
- Correlate password-reset initiation events with password-reset completion events and alert when the target account differs across the two stages.
- Inspect web server and application logs for anomalous POST requests to the recovery endpoint containing enumerated or sequential identifier values.
- Deploy Web Application Firewall (WAF) rules that decode the recovery JWT and compare its subject claim against the usuariId body parameter.
Monitoring Recommendations
- Alert on any successful authentication that immediately follows a password reset for administrative or high-privilege accounts.
- Track baseline volumes for the /password/guardarClau/recover endpoint and flag spikes indicative of enumeration.
- Forward authentication and password-management logs to a centralized data lake to enable cross-source correlation and hunting.
How to Mitigate CVE-2026-93556
Immediate Actions Required
- Apply the vendor patch once available and confirm the recovery endpoint validates the JWT subject against usuariId.
- Invalidate all outstanding password recovery tokens to prevent replay against unrelated accounts.
- Force a password reset for administrator accounts and audit recent password changes for anomalies.
- Enable multi-factor authentication (MFA) on privileged accounts to reduce the impact of a successful password reset.
Patch Information
No vendor advisory or fixed version is listed in the NVD entry at publication. Refer to the Incibe Security Notice on IDOR for advisory updates and contact the vendor for a patched release.
Workarounds
- Restrict the /password/guardarClau/recover endpoint at the reverse proxy or WAF to enforce that the decoded JWT subject equals the submitted usuariId.
- Remove the usuariId parameter from the request contract and derive the target account solely from the JWT claim on the server side.
- Rate-limit and geofence the password recovery endpoint to slow enumeration attempts while a permanent fix is prepared.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
