CVE-2026-57868: MicroRealEstate Auth Bypass Vulnerability

CVE-2026-57868 Overview

CVE-2026-57868 is a broken object-level authorization flaw in MicroRealEstate, an open-source property management platform. The vulnerability affects the PDF generator functionality through version 1.0.0-alpha3. Authenticated users can access PDF documents belonging to other tenants or organizations by manipulating object identifiers in requests. The underlying weakness is classified as [CWE-639] Authorization Bypass Through User-Controlled Key. Exploitation requires low privileges and no user interaction over the network. Successful attacks expose confidential tenant, lease, and financial data rendered in generated PDFs.

Critical Impact
Authenticated attackers can retrieve PDF documents belonging to other users or organizations, resulting in disclosure of sensitive property management, tenant, and financial records.

Affected Products

MicroRealEstate through 1.0.0-alpha3
PDF generator microservice component
Deployments exposing the PDF generation endpoint to authenticated users

Discovery Timeline

2026-07-07 - CVE-2026-57868 published to NVD
2026-07-07 - Last updated in NVD database

Technical Details for CVE-2026-57868

Vulnerability Analysis

MicroRealEstate is a microservice-based property management application that generates PDF documents such as leases, invoices, and receipts. The PDF generator service exposes endpoints that accept object identifiers referencing tenants, contracts, or billing records. The application authenticates the caller but does not verify that the caller owns or has authorization to access the requested object. An attacker with any valid low-privilege account can enumerate or guess identifiers and retrieve documents belonging to other organizations. This is a classic Insecure Direct Object Reference (IDOR) pattern in a multi-tenant SaaS-style deployment.

Root Cause

The root cause is missing object-level authorization ([CWE-639]) in the PDF generator route handlers. The service trusts identifiers supplied by the client and resolves them directly against the data store without cross-checking the requesting user's organization or role. Authentication is enforced, but authorization decisions do not include the object's ownership context.

Attack Vector

An authenticated attacker sends a crafted HTTP request to the PDF generator endpoint with an object identifier that does not belong to their account. The server generates and returns the corresponding PDF, disclosing another tenant's information. The attack is network-accessible, requires no user interaction, and can be scripted to enumerate identifiers at scale. Technical details are available in the The Missing Link Security Advisory and the MicroRealEstate GitHub repository.

Detection Methods for CVE-2026-57868

Indicators of Compromise

Repeated HTTP requests to PDF generator endpoints with sequential or varied object identifiers from a single account.
Successful 200 OK responses returning PDF payloads for identifiers outside a user's normal access pattern.
Anomalous volumes of PDF download activity from newly created or low-privilege accounts.

Detection Strategies

Correlate authenticated user IDs against the tenant or organization scope of accessed object identifiers in application logs.
Alert on account behavior that requests documents across many distinct organization IDs within short time windows.
Review reverse proxy and application access logs for enumeration patterns targeting PDF routes.

Monitoring Recommendations

Enable verbose request logging on the PDF generator microservice, capturing user ID, requested object ID, and organization context.
Forward application and gateway logs to a centralized analytics platform for cross-account access analysis.
Establish per-account baselines for PDF retrieval rates and trigger alerts on statistical deviations.

How to Mitigate CVE-2026-57868

Immediate Actions Required

Restrict access to the MicroRealEstate PDF generator endpoints to trusted networks or authenticated administrative users until a patched release is available.
Audit recent PDF generation logs for cross-tenant access and notify affected organizations if data disclosure is confirmed.
Rotate any credentials, tokens, or identifiers exposed in leaked PDF contents.

Patch Information

At the time of publication, no fixed release beyond 1.0.0-alpha3 is referenced in the advisory. Monitor the MicroRealEstate GitHub repository for updates and apply patched versions as soon as they are published.

Workarounds

Add authorization middleware in front of the PDF generator service to validate that the requesting user's organization matches the object's owning organization.
Replace sequential or predictable object identifiers with unguessable UUIDs to reduce enumeration feasibility, while still enforcing server-side authorization.
Limit the PDF generator service to internal network access and require an authorization proxy for external requests.

bash

# Example reverse proxy rule to restrict PDF endpoints to internal networks
location /api/v2/pdfgenerator/ {
    allow 10.0.0.0/8;
    deny all;
    proxy_pass http://pdfgenerator:8083;
}