CVE-2026-21279 in ColdFusion
Summary
by MITRE • 08/11/2026
is affected by an Improper Input Validation vulnerability that could result in a Security feature bypass. An attacker could leverage this vulnerability to bypass security measures and gain unauthorized read and limited write access. Exploitation of this issue does not require user interaction.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical weakness in input validation mechanisms that enables attackers to circumvent security controls without requiring any user interaction. The improper handling of input data creates a pathway for malicious actors to bypass authentication, authorization, or other protective measures that should normally prevent unauthorized access to system resources. The security feature bypass occurs when the system fails to properly validate or sanitize incoming data, allowing crafted inputs to be processed as if they were legitimate requests. This flaw specifically enables unauthorized read access to sensitive information and limited write capabilities, suggesting that while attackers cannot fully compromise the system, they can still extract valuable data and potentially modify certain resources within defined boundaries.
The technical nature of this vulnerability aligns with common weakness patterns identified in the CWE database, particularly those related to input validation failures such as CWE-20 for Improper Input Validation and CWE-16 for Configuration. The absence of user interaction requirements makes this vulnerability especially dangerous as it can be exploited automatically through automated tools or scripts without the need for social engineering or direct user engagement. Attackers can craft malicious inputs that exploit the validation gaps, potentially leading to data exfiltration or unauthorized modifications of system components. This type of vulnerability often stems from inadequate sanitization of user-supplied data, lack of proper bounds checking, or insufficient validation of input formats and content types.
The operational impact of this security flaw extends beyond simple data access issues as it fundamentally undermines the integrity of the system's security model. Organizations may experience unauthorized data reading through the bypassed controls, potentially exposing confidential information or sensitive system details that should remain protected. The limited write access capability suggests that while complete system compromise is not immediately possible, attackers can still make modifications to specific resources or configurations within the scope of their privileges. This vulnerability can be particularly damaging when combined with other weaknesses in the system architecture, as it provides a foothold for more extensive attacks and potentially lateral movement within network environments.
Effective mitigation strategies should focus on implementing robust input validation controls that enforce strict data type, format, and size limitations before processing any user-supplied information. Organizations must establish comprehensive sanitization procedures that filter out potentially malicious content and ensure all inputs are properly validated against expected patterns and ranges. Security measures should include regular code reviews focused on input handling routines, implementation of automated testing for validation weaknesses, and deployment of web application firewalls to monitor and block suspicious traffic patterns. Additionally, principle of least privilege configurations should be enforced to limit the potential impact even if an attacker successfully exploits the vulnerability, ensuring that bypassed controls do not grant excessive permissions or access to critical system components. The remediation efforts must address both the immediate validation gaps and strengthen overall input handling mechanisms throughout the application stack to prevent similar vulnerabilities from emerging in future versions.