CVE-2026-102489 in Zammad
Summary
by MITRE • 09/30/2026
Zammad versions 6.3.0 to 6.5.4 are vulnerable a session hijack vulnerability that leads to remote code execution as the zammad user. The vulnerability is also present in version 7.0.0 to version 7.1.3, but not exploitable due to environment conditions.
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Analysis
by VulDB Data Team • 09/30/2026
Zammad versions ranging from 6.3.0 through 6.5.4 contain a critical session hijacking flaw that can be leveraged by an attacker to achieve remote code execution under the context of the zammad application user. This vulnerability stems from insufficient validation and management of session identifiers within the web application framework, allowing malicious actors to intercept or forge valid session tokens. By exploiting this weakness, an adversary can impersonate legitimate users without requiring authentication credentials, effectively bypassing access controls that are designed to restrict functionality based on user roles and permissions. The presence of similar code patterns in versions 7.0.0 through 7.1.3 indicates a systemic issue within the session handling logic across multiple major releases, although environmental configurations or additional security mitigations in those later versions currently prevent successful exploitation.
The technical mechanism behind this vulnerability aligns with CWE-384, Session Fixation, and CWE-613, Insufficient Session Expiration, as it involves the improper management of session state during user interactions. When a session token is not properly regenerated upon authentication or when sensitive data is transmitted over insecure channels without adequate integrity checks, attackers can inject their own session identifiers into the victim's browser context. This allows them to maintain persistent access even after password changes or logout actions if proper invalidation procedures are not enforced at the server level. The exploitation path typically involves crafting specific HTTP requests that manipulate cookie values or URL parameters containing session data, thereby tricking the application into associating the attacker’s input with a privileged user account.
The operational impact of this vulnerability is severe due to its direct progression from unauthorized access to full system compromise. Once an attacker successfully hijacks a valid session belonging to an administrator or a user with elevated privileges within Zammad, they gain the ability to execute arbitrary commands on the underlying server infrastructure. Since Zammad operates as a customer relationship management and ticketing platform often deployed in enterprise environments, compromising its integrity can lead to significant data breaches involving sensitive customer information, communication logs, and internal organizational details. The execution of code under the zammad user account provides attackers with persistent footholds within the network, facilitating lateral movement toward other critical systems and potentially leading to complete infrastructure takeover if not detected and remediated promptly.
To mitigate this risk, organizations running affected versions must immediately upgrade to a patched release where session management practices have been hardened according to industry best standards such as OWASP Session Management guidelines. It is essential to ensure that all sessions are invalidated upon logout, password changes, or privilege escalations, and that new session identifiers are generated for every authenticated request. Additionally implementing secure cookie attributes including HttpOnly, Secure, and SameSite flags can reduce the surface area available for cross-site scripting attacks that often precede session hijacking attempts. Security teams should also monitor access logs for anomalous patterns such as sudden changes in user agent strings or IP addresses associated with active sessions, which may indicate ongoing exploitation activities against unpatched instances of Zammad.