CVE-2026-90566: Inventory Management System Auth Bypass

CVE-2026-90566 is an authentication bypass flaw in Rizwan17 inventory-management-system affecting the user registration process. Attackers can manipulate usertype parameters to gain unauthorized access. This article covers technical details, exploit availability, impact assessment, and recommended security measures.

CVE-2026-90566 Overview

CVE-2026-90566 is an improper authorization vulnerability [CWE-266] in the Rizwan17 inventory-management-system project. The flaw resides in the createUserAccount function of register.php within the Registration Handler component. An attacker can manipulate the usertype argument during registration to obtain a privilege level that should not be available to unauthenticated users. The attack is exploitable remotely over the network without authentication or user interaction. Because the project follows a rolling-release model, no versioned patch is available, and the maintainer has not responded to the disclosure. A public exploit description has been referenced, increasing the likelihood of opportunistic abuse against exposed deployments.

Critical Impact
Unauthenticated remote attackers can register accounts with elevated usertype values, resulting in privilege escalation against affected instances.

Affected Products

Rizwan17 inventory-management-system up to commit bfe78a330d01bb26b9daec5dc9ecd5c77900e03f
Component: Registration Handler (register.php)
Function: createUserAccount

Discovery Timeline

2026-09-13 - CVE-2026-90566 published to NVD
2026-09-14 - Last updated in NVD database

Technical Details for CVE-2026-90566

Vulnerability Analysis

The vulnerability exists in the account registration flow exposed by register.php. The createUserAccount function accepts a usertype parameter directly from the client request and uses it when creating the new user record. Because the server does not enforce a server-side authorization check on the value, any caller can request an administrative or elevated role. This is a classic Incorrect Privilege Assignment issue captured under [CWE-266]. Successful exploitation grants the attacker persistent access to functionality intended for privileged roles, including inventory data manipulation. The absence of vendor response and the rolling-release delivery model mean no fixed version identifier is available for defenders to pin to.

Root Cause

The root cause is trust of client-supplied role data. The usertype field is treated as authoritative rather than being derived server-side or constrained to a safe default such as a standard user. No allow-list, session context check, or server-side policy enforces which usertype values a self-registering caller may claim.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker submits a crafted HTTP POST request to the registration endpoint containing standard registration fields plus a manipulated usertype value that maps to an elevated role. The application accepts the value and provisions the account with that privilege. The attacker then authenticates normally and operates with elevated rights.

No verified proof-of-concept code is published for this article. Refer to the VulDB CVE-2026-90566 Entry and the GitHub Issue #16 Discussion for technical context.

Detection Methods for CVE-2026-90566

Indicators of Compromise

POST requests to register.php containing a usertype parameter with a value corresponding to an administrator or elevated role.
Newly created accounts with privileged usertype values that were not provisioned by an existing administrator.
Authentication events from newly registered accounts immediately followed by access to administrative pages or inventory-modification endpoints.

Detection Strategies

Inspect web server and application logs for registration requests where the submitted usertype differs from the default role assigned to self-service registrations.
Query the user database for accounts whose role field was set outside of an administrator-driven workflow.
Correlate account creation events with subsequent privileged actions performed within a short time window.

Monitoring Recommendations

Alert on any HTTP request to /register.php that includes the usertype field in the body or query string.
Monitor for spikes in account creation from a single source IP or user agent.
Track administrative role assignments and generate an alert when the source of the change is the public registration endpoint rather than an administrator session.

How to Mitigate CVE-2026-90566

Immediate Actions Required

Restrict access to register.php at the reverse proxy or web server layer until a code-level fix is in place.
Modify createUserAccount to ignore any client-supplied usertype value and assign the lowest-privilege role by default.
Audit all existing accounts and remove or downgrade any that were provisioned with unexpected elevated usertype values.

Patch Information

No vendor patch is available. The project uses rolling releases and, according to the CVE record, the maintainer has not responded to the issue report tracked in the GitHub Issue #16 Discussion. Operators should apply a local code fix that enforces server-side role assignment and reject any request that attempts to set usertype from user-controlled input.

Workarounds

Place the application behind an authenticated reverse proxy so unauthenticated users cannot reach register.php.
Disable public self-registration and provision users manually through a trusted administrative workflow.
Add a web application firewall rule that strips or blocks the usertype parameter on requests to the registration endpoint.

bash

# Example ModSecurity rule to block usertype tampering on registration
SecRule REQUEST_URI "@endsWith /register.php" \
    "phase:2,chain,deny,status:403,id:1029056,msg:'CVE-2026-90566: usertype parameter blocked on registration'"
    SecRule ARGS_NAMES "@streq usertype" "t:lowercase"