CVE-2026-19864 in Jetty
Summary
by MITRE • 10/15/2026
Eclipse Jetty's `SessionAuthentication` retains authentication credentials in a serializable object. When the credentials contain a plaintext password and the authenticated session is persisted to a session data store, the password may consequently be written to persistent storage in plaintext.
An attacker with sufficient privileges to read the persisted session data may obtain the plaintext passwords of authenticated users.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified within Eclipse Jetty's SessionAuthentication component represents a critical flaw in how authentication credentials are managed during session persistence operations. This issue stems from the design choice where the SessionAuthentication object is implemented as serializable, allowing it to be easily converted into a byte stream for storage or transmission across distributed systems. While serialization provides necessary flexibility for state management in web applications, it introduces significant security risks when sensitive data such as plaintext passwords are included within the serialized payload without adequate protection mechanisms like encryption or hashing prior to persistence.
When an application utilizes Jetty's session management features and stores authenticated sessions in a persistent backend store, such as a database, file system, or distributed cache, the entire SessionAuthentication object is written to that storage medium. If the authentication mechanism employed by the application relies on storing plaintext passwords within this object for subsequent validation steps, those credentials are effectively saved in their original form. This occurs because the serialization process does not inherently strip out sensitive fields or apply cryptographic transformations; it merely preserves the state of the object exactly as it exists in memory at the time of persistence.
The operational impact of this vulnerability is severe, particularly in environments where session data stores may be accessed by multiple services, administrators, or backup systems with varying levels of security controls. An attacker who gains sufficient privileges to read from these persistent storage locations can extract the serialized session data and deserialize it back into its object form. Once deserialized, any plaintext passwords contained within the SessionAuthentication structure become immediately accessible in clear text. This exposure bypasses standard password hashing practices that are typically applied during user registration or login validation, leaving credentials vulnerable to offline cracking attacks if they were weak, or direct account takeover if strong unique passwords were used across multiple services due to credential stuffing risks.
This flaw aligns with CWE-312, which describes the issue of storing sensitive data in cleartext within a non-volatile storage medium. It also relates to CWE-524 regarding the use of cache that contains sensitive information without proper protection, as session stores often function similarly to caches for performance optimization. From an adversarial perspective, this vulnerability facilitates privilege escalation and unauthorized access by allowing attackers to harvest credentials directly from backend infrastructure rather than targeting application logic or network traffic interception points.
To mitigate this risk, developers must ensure that plaintext passwords are never included in objects intended for serialization and persistent storage. Authentication mechanisms should rely on secure token-based systems such as JSON Web Tokens (JWT) with signed payloads or opaque session identifiers that reference server-side state without exposing the underlying credentials. If legacy authentication methods requiring password verification during sessions are necessary, the system must implement robust encryption of sensitive fields before they enter any serializable structure. Additionally, employing memory-safe coding practices and regularly auditing serialization logic against OWASP guidelines can prevent similar exposures in future development cycles.