CVE-2026-5799: Ontime Authorization Bypass Vulnerability

CVE-2026-5799 Overview

CVE-2026-5799 is an authorization bypass vulnerability in Idvlabs Software and Consulting Services Inc. Ontime. The flaw stems from improper handling of user-controlled keys, which allows attackers to exploit trusted identifiers to access resources belonging to other users. The vulnerability is categorized under [CWE-639] (Authorization Bypass Through User-Controlled Key), a class commonly known as Insecure Direct Object Reference (IDOR). All Ontime versions through build 04052026 are affected. An unauthenticated attacker can exploit this issue over the network without user interaction, leading to disclosure of sensitive information.

Critical Impact
Remote attackers can access confidential data belonging to other users by manipulating trusted identifiers in requests, without requiring authentication or user interaction.

Affected Products

Idvlabs Software and Consulting Services Inc. Ontime (all versions through 04052026)

Discovery Timeline

2026-07-07 - CVE-2026-5799 published to NVD
2026-07-07 - Last updated in NVD database

Technical Details for CVE-2026-5799

Vulnerability Analysis

The vulnerability resides in how the Ontime application handles resource identifiers supplied by clients. The application accepts identifiers in requests and returns the associated resource without validating whether the requesting user has authorization to access that resource. This pattern is a classic Insecure Direct Object Reference (IDOR) issue tracked under [CWE-639].

Because the attack vector is network-based and requires no privileges or user interaction, an unauthenticated actor can iterate through predictable identifiers to enumerate and retrieve records belonging to other accounts. The impact is limited to confidentiality; integrity and availability are not affected according to the published metrics.

Root Cause

The root cause is missing server-side authorization checks on API endpoints that accept user-controlled keys such as record IDs, tokens, or reference numbers. The application trusts the identifier without verifying the requester's ownership or permissions over the target object.

Attack Vector

An attacker sends crafted HTTP requests to Ontime endpoints, substituting identifier values (for example, numeric record IDs or user references) with values belonging to other users. The server processes the request and returns the referenced object without enforcing an ownership check. This enables mass enumeration of records where identifiers follow predictable sequences.

No verified exploit code is publicly available. Refer to the Siber Guvenlik Advisory TR-26-0503 for additional technical detail.

Detection Methods for CVE-2026-5799

Indicators of Compromise

Sequential or non-sequential enumeration of identifier parameters (such as id=, userId=, recordId=) in web server access logs from a single source.
High-volume HTTP 200 responses to requests with varied identifier values from unauthenticated sessions.
Unusual data exfiltration patterns tied to Ontime application endpoints.

Detection Strategies

Deploy web application firewall (WAF) rules to alert on rapid iteration of identifier parameters against Ontime endpoints.
Correlate application logs to identify sessions accessing resources across many distinct owner IDs within short time windows.
Monitor for anomalous outbound response sizes from Ontime services that could indicate bulk data retrieval.

Monitoring Recommendations

Enable verbose application-layer logging on Ontime, capturing authenticated user context alongside the requested resource identifier.
Establish baselines for typical identifier access patterns per session and alert on statistical deviations.
Forward Ontime access logs to a centralized SIEM for correlation with authentication events and threat intelligence.

How to Mitigate CVE-2026-5799

Immediate Actions Required

Contact Idvlabs Software and Consulting Services Inc. to obtain a patched build later than 04052026.
Restrict network exposure of Ontime to trusted networks or place the application behind an authenticating reverse proxy until a patch is applied.
Audit application logs for evidence of identifier enumeration or unauthorized data access.

Patch Information

The advisory Siber Guvenlik Advisory TR-26-0503 tracks remediation status. Users should apply any vendor-supplied build released after 04052026. Confirm with the vendor that server-side authorization checks have been added to affected endpoints.

Workarounds

Implement a reverse proxy or API gateway that enforces per-user authorization based on session identity before proxying requests to Ontime.
Replace predictable sequential identifiers with unguessable values (such as UUIDs) at the proxy layer where feasible.
Apply rate limiting on identifier-bearing endpoints to slow enumeration attempts.
Restrict Ontime access to VPN or SSO-gated networks until a vendor patch is deployed.

bash

# Example nginx rate limit for endpoints accepting record identifiers
limit_req_zone $binary_remote_addr zone=ontime_ids:10m rate=10r/m;

location /api/ {
    limit_req zone=ontime_ids burst=5 nodelay;
    proxy_pass http://ontime_backend;
}