CVE-2026-77337 in Authentication
Summary
by MITRE • 08/25/2026
CakePHP Authentication is an authentication plugin for CakePHP that can also be used in PSR-7 based applications. Versions before 2.11.2, from 3.0.0 through 3.3.6, and from 4.0.0 through 4.2.0 allow authentication bypass and potential CPU or memory exhaustion when CookieAuthenticator uses unencrypted, forgeable legacy tokens. This issue is fixed in versions 2.11.2, 3.3.7, and 4.2.1.
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Analysis
by VulDB Data Team • 08/25/2026
The CakePHP Authentication plugin serves as a critical component for managing user identity verification within the CakePHP framework and compatible PSR-7 based applications. It provides various strategies to authenticate users against different sources such as databases, external services, or session data. However, in versions prior to 2.11.2, specifically ranging from 3.0.0 through 3.3.6, and from 4.0.0 through 4.2.0, a significant security flaw exists within the CookieAuthenticator implementation. This vulnerability stems from the use of unencrypted tokens for session management when cookies are employed as the authentication mechanism. The core technical issue lies in the fact that these legacy tokens lack integrity protection and encryption, making them susceptible to forgery by attackers who can manipulate or create valid-looking credentials without possessing legitimate user secrets.
This architectural weakness allows for a direct authentication bypass, enabling unauthorized users to impersonate other accounts simply by crafting malicious cookie values. Beyond the immediate risk of privilege escalation and data exposure, the vulnerability also presents a potential vector for denial-of-service attacks. Because the server must process these forged tokens during every request validation cycle, an attacker can generate high volumes of malformed or computationally expensive token structures. This behavior can lead to significant CPU exhaustion or memory depletion on the backend servers as they attempt to validate numerous invalid credentials, thereby degrading service availability for legitimate users.
From a classification perspective, this vulnerability aligns with CWE-287, which describes Improper Authentication, specifically regarding the failure to verify identity correctly due to weak credential handling mechanisms. It also relates to CWE-345, Insufficient Verification of Data Integrity, as the system fails to ensure that the authentication token has not been tampered with or forged by an external party. In terms of offensive security tactics, this flaw facilitates Initial Access via Valid Accounts under the MITRE ATT&CK framework, allowing adversaries to bypass standard login controls and establish persistent access within the application environment without detection through traditional credential monitoring systems.
The operational impact of this vulnerability is severe for any production system relying on cookie-based authentication with these affected versions. Administrators face risks ranging from complete compromise of user data integrity to potential service disruption due to resource exhaustion attacks. The ability to forge tokens means that session hijacking and account takeover become trivial exercises for anyone capable of intercepting or guessing the token structure, especially if additional entropy is low in the generation process. This undermines the fundamental trust model of web applications where cookies are expected to provide a secure stateful context between client and server interactions.
To mitigate this risk, organizations must upgrade immediately to version 2.11.2 for legacy systems or versions 3.3.7 and 4.2.1 for modern deployments. These updated releases address the underlying cryptographic weaknesses by implementing proper encryption and integrity checks for cookie-based tokens. In addition to upgrading, developers should review their authentication configurations to ensure that sensitive data is never stored in plaintext within cookies and consider adopting more robust session management practices such as server-side sessions with secure identifiers rather than client-stored credentials where possible. Regular security audits and dependency updates are essential to maintain resilience against evolving threats targeting web application frameworks.