CVE-2026-18363 in osTicket
Summary
by MITRE • 07/30/2026
A logic vulnerability in the password reset token validation routine implemented by osTicket in versions prior to v1.17.8 and v1.18.4. During the password reset process, the application retrieves the timestamp associated with the provided token and checks whether the configured validity period has expired. Consequently, the expiry check is only performed if the timestamp lookup fails, allowing tokens with an existing timestamp to bypass the intended expiry validation. Therefore, an attacker able to obtain a valid password reset token could reuse it to perform an unauthorised password reset and compromise the affected account.
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical logic flaw in the authentication security mechanism of osTicket ticketing systems, specifically affecting versions prior to v1.17.8 and v1.18.4. The issue resides within the password reset token validation routine where the application follows an incorrect conditional execution flow that fundamentally undermines the intended security controls. The vulnerability stems from a flawed implementation pattern where timestamp verification occurs before expiration validation, creating a logical race condition that allows attackers to exploit the system's authentication flow.
The technical flaw manifests as a classic improper validation logic error that violates fundamental security principles. When a user initiates a password reset request, osTicket generates a token with an associated timestamp and sets a configurable validity period. However, during the validation process, the system first attempts to retrieve the timestamp from the token and only performs the expiration check if this lookup fails or returns null values. This creates a dangerous condition where tokens that successfully pass the timestamp retrieval phase automatically bypass all subsequent expiration verification steps regardless of their actual age or validity status.
From an operational perspective, this vulnerability presents a severe risk to account security and system integrity. An attacker who manages to obtain a valid password reset token through various means such as social engineering, session hijacking, or prior compromise can indefinitely reuse that token to reset passwords for compromised accounts. The vulnerability essentially creates a backdoor that allows unauthorized access to any account that has received a valid reset token, regardless of how much time has passed since the token was initially generated. This undermines the core principle of time-based token expiration that is fundamental to secure authentication systems.
The impact of this vulnerability aligns with CWE-697, which specifically addresses "Incorrect Comparison" in security contexts where logical conditions fail to properly validate security-relevant data. From an ATT&CK framework perspective, this represents a privilege escalation and credential access vector under technique T1566 (Phishing) and T1078 (Valid Accounts) where the attacker can leverage stolen tokens to gain unauthorized access. The vulnerability also demonstrates poor input validation practices that violate security best practices outlined in NIST SP 800-63B for authentication system design, particularly concerning session management and token lifecycle controls.
Organizations using affected osTicket versions should immediately implement the available patches released in v1.17.8 and v1.18.4 to address this logic flaw. In addition to patching, administrators should consider implementing additional security measures such as monitoring for unusual password reset patterns, enforcing stricter token generation policies, and implementing multi-factor authentication where possible. The vulnerability highlights the critical importance of proper conditional logic implementation in security-critical components and demonstrates how seemingly minor code ordering issues can create significant security weaknesses that compromise entire authentication systems.