CVE-2026-5555: SQL Injection in Concert Ticket Reservation System Login

CVE-2026-5555: SQL Injection — Authentication Bypass in Concert Ticket Reservation System

A SQL injection vulnerability tracked as CVE-2026-5555 has been disclosed in code-projects Concert Ticket Reservation System 1.0. Unlike a typical data-exposure injection, this flaw resides in the application's login form at login.php, meaning it can be exploited by completely unauthenticated users to bypass authentication entirely and gain full admin access without a valid password.

The vulnerability was assigned a CVSS v3.1 score of 7.3 (High) and classified under CWE-89 — Improper Neutralization of Special Elements used in SQL Commands.

Vulnerability Overview

Technical Details

Affected Component

The vulnerability exists in the authentication module of the Concert Ticket Reservation System. The login.php file accepts an Email parameter and incorporates it directly into a SQL query to verify user credentials. Because no parameterization or escaping is applied, an attacker can manipulate the query logic to authenticate as any user — including administrators — without knowing the actual password.

Exploitation Mechanism

Login-page SQL injection is among the most severe variants of this vulnerability class, as it requires zero prior access. An attacker simply submits a crafted email value that short-circuits the credential verification query:

POST /ConcertTicketReservationSystem-master/login.php
Email=' OR '1'='1'--&Password=anything
Email=admin@example.com'--&Password=ignored
Email=' UNION SELECT 1,'admin','hash',1--&Password=anything

The injected payload transforms the login query from:

SELECT * FROM users WHERE email = '[input]' AND password = '[hash]'

Into a query that always returns true or returns the admin row directly, granting full administrative access without a valid password.

Beyond authentication bypass, if error-based or UNION-based injection is successful, an attacker can also:

• Dump the entire user database — all email addresses, password hashes, and personal data
• Enumerate all database tables — including event schedules, booking records, and payment history
• Exfiltrate admin credentials — for lateral movement if credentials are reused elsewhere

Attack Flow

1. Attacker navigates to the public login page of an exposed Concert Ticket instance

2. Attacker enters a crafted SQL payload in the Email field (e.g., ' OR '1'='1'--)

3. login.php incorporates the raw input directly into a credential-lookup SQL query

4. The injected logic bypasses the WHERE clause, returning the first user (admin)

5. Attacker is authenticated as administrator with full application access

6. From the admin panel, attacker can access all bookings, user PII, and system settings

Affected Software Context

code-projects distributes open-source PHP applications for academic and educational use. The Concert Ticket Reservation System 1.0 is a lightweight ticketing platform used by students and developers learning PHP web application development.

The login-page injection vulnerability is especially critical because it requires no prior access or credentials, making automated exploitation trivially easy. Any internet-accessible instance of this application is at immediate risk of full compromise. This CVE is closely related to CVE-2026-5554 (search page injection), disclosed the same day, suggesting the application has not had any security review prior to distribution.

Remediation

Immediate Steps

No official patch is available. Operators must act immediately:

1. Take the application offline or block all public access — A login bypass means any internet-accessible instance is fully compromised
2. Rotate all application and database credentials — Assume any existing credentials have been harvested
3. Audit authentication logs — Look for successful logins from unexpected IP addresses or outside normal operating hours
4. Deploy a Web Application Firewall (WAF) — Apply SQL injection blocking rules as an emergency mitigation while the code is updated
5. Patch the login query — Replace raw string interpolation with parameterized PDO queries

Code-Level Fix

// Vulnerable pattern
$query = "SELECT * FROM users WHERE email = '" . $_POST['Email'] . "' AND password = '" . $hashed . "'";
 
// Secure pattern (PDO prepared statement)
$stmt = $pdo->prepare("SELECT * FROM users WHERE email = ? AND password = ?");
$stmt->execute([$_POST['Email'], $hashed]);

Additionally, implement bcrypt or Argon2 for password hashing rather than MD5 or SHA1, which are commonly used in code-projects applications.

Impact Assessment

Relationship to CVE-2026-5554

This CVE was disclosed on the same day as CVE-2026-5554, which targets the process_search.php search endpoint in the same application. Both vulnerabilities share the same root cause — unsanitized SQL query construction — indicating the Concert Ticket Reservation System 1.0 has not undergone any security review. Operators should treat the entire application as untrusted and conduct a full code audit before any production deployment.

Key Takeaways

1. CVE-2026-5555 is a CVSS 7.3 SQL injection in the login form of code-projects Concert Ticket Reservation System 1.0
2. The Email parameter is passed directly into a credential-lookup SQL query, enabling complete authentication bypass
3. This is a pre-authentication vulnerability — no existing account or credentials are needed to exploit it
4. No official patch exists — take any public-facing instances offline immediately
5. Paired with CVE-2026-5554, this reflects a systemic input validation failure across the entire application

Sources

• CVE-2026-5555 — NIST NVD