CVE-2026-21695: Titra Auth Bypass Vulnerability

CVE-2026-21695 Overview

CVE-2026-21695 is a Mass Assignment vulnerability affecting Titra, an open source project time tracking software. The vulnerability exists in versions 0.99.49 and below, where an API endpoint allows authenticated users to inject arbitrary fields into time entries by exploiting the customfields parameter. This bypasses business logic controls and enables attackers to overwrite protected database fields.

Critical Impact

Authenticated attackers can manipulate protected time entry fields including userId, hours, and state, potentially leading to data integrity compromise and business logic bypass in time tracking operations.

Affected Products

• Titra versions 0.99.49 and below
• Titra time tracking API endpoints handling customfields parameter

Discovery Timeline

• 2026-01-08 - CVE-2026-21695 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2026-21695

Vulnerability Analysis

This vulnerability is classified as CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes), commonly known as Mass Assignment. The affected API endpoints in Titra merge user-controlled input directly into database documents without proper field validation.

While the application validates that customfields is an Object type, it fails to implement an allowlist of permitted keys within that object. This architectural flaw allows authenticated users to inject arbitrary key-value pairs that get merged into the final database document, effectively overwriting fields that should be immutable or protected.

The vulnerability requires network access and authenticated user privileges to exploit. The primary impact is integrity-related, as attackers can manipulate time entry data without affecting confidentiality or availability directly.

Root Cause

The root cause lies in the unsafe use of the JavaScript spread operator (...customfields) to merge user-controlled input into database documents. The spread operator position in the object literal determines which values take precedence—when ...customfields appears after protected fields like userId and hours, the user-supplied values can overwrite the application-controlled values.

The application performs type validation ensuring customfields is an Object, but lacks validation of the specific keys permitted within that object. Without an allowlist or blocklist mechanism, any field name accepted by the database schema becomes a target for manipulation.

Attack Vector

The attack is executed over the network by an authenticated user sending a malicious API request. The attacker crafts a request with a customfields object containing protected field names (such as userId, hours, or state) with attacker-controlled values. When the server processes this request, the spread operator merges these malicious fields, overwriting the legitimate values.

For example, an attacker could submit time entries attributed to other users, manipulate logged hours, or change the state of time entries to bypass approval workflows.

// Vulnerable code pattern (before fix) in imports/api/timecards/server/methods.js
async function insertTimeCard(projectId, task, date, hours, userId, taskRate, customfields) {
  const newTimeCard = {
    userId,
    projectId,
    date,
    hours,
    task: await emojify(task),
    ...customfields,  // User input spread AFTER protected fields - can overwrite!
  }
  // ...
}

Source: GitHub Commit Update

// Fixed code pattern (after fix) - spread operator moved to beginning
async function insertTimeCard(projectId, task, date, hours, userId, taskRate, customfields) {
  const newTimeCard = {
    ...customfields,  // User input spread FIRST - protected fields override any malicious input
    userId,
    projectId,
    date,
    hours,
    task: await emojify(task),
  }
  // ...
}

Source: GitHub Commit Update

Detection Methods for CVE-2026-21695

Indicators of Compromise

• Unexpected modifications to time entry userId fields showing entries attributed to different users than those who created them
• Anomalous hours values in time entries that deviate significantly from normal patterns
• Time entry state field changes occurring outside of normal workflow processes
• API requests containing customfields parameters with suspicious key names matching protected field names

Detection Strategies

• Implement API request logging that captures the full customfields object contents for forensic analysis
• Deploy application-layer monitoring to alert on API requests where customfields contains keys matching protected field names (userId, hours, state, projectId)
• Analyze database audit logs for time entries where the recorded userId differs from the authenticated user making the request
• Review time entry modification patterns for signs of unauthorized attribute manipulation

Monitoring Recommendations

• Enable detailed logging on Titra API endpoints handling time card and task operations
• Set up alerts for bulk time entry modifications or unusual patterns of field value changes
• Monitor for authenticated users making API calls with unusually large or complex customfields objects
• Implement database-level triggers or audit logging to track modifications to sensitive fields

How to Mitigate CVE-2026-21695

Immediate Actions Required

• Upgrade Titra to version 0.99.50 or later immediately to address this vulnerability
• Review recent time entries for signs of unauthorized field manipulation, particularly focusing on userId, hours, and state fields
• Audit user permissions to ensure only trusted users have API access until the patch is applied
• Consider implementing additional API input validation at the reverse proxy or WAF level as a defense-in-depth measure

Patch Information

The vulnerability is fixed in Titra version 0.99.50. The patch modifies the object spread operator position to ensure that user-controlled customfields are applied first, with protected fields explicitly defined afterward. This ensures that application-controlled values always take precedence over any attacker-supplied fields.

The fix was implemented in commit 29e6b88eca005107729e45a6f1731cf0fa5f8938. For detailed information, refer to the GitHub Security Advisory GHSA-gc65-vr47-jppq.

Workarounds

• Implement server-side input validation to strip or reject any customfields containing protected key names before processing
• Deploy a Web Application Firewall (WAF) rule to inspect and block API requests with suspicious customfields payloads
• Restrict API access to a minimal set of trusted users until the official patch can be applied
• Implement database-level constraints or triggers to prevent modifications to protected fields from unexpected sources

# Configuration example - upgrading Titra to patched version
# Pull the latest version from the repository
git fetch origin
git checkout v0.99.50

# Or if using npm/yarn
npm update titra@0.99.50

# Restart the Titra service after updating
systemctl restart titra