CVE-2026-123094 in Huginn
Summary
by MITRE • 11/05/2026
Huginn before 2026.11.05 contains a stored cross-site scripting vulnerability in the service_label helper that marks unescaped OAuth service display names as html_safe. Authenticated attackers can connect an OAuth account with a crafted nickname, name or email and share it globally, executing JavaScript when victims attach it to Agents and view them, exposing Credentials, Agents and Events, and admin actions if the victim is an administrator.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability identified in Huginn versions prior to 2026.11.05 represents a critical stored cross-site scripting (XSS) flaw located within the service_label helper component of the application's rendering logic. This specific implementation error arises from the improper handling of user-supplied input derived from OAuth authentication providers. When an authenticated user connects their Huginn instance to an external identity provider, such as Google or GitHub, the system retrieves metadata including display names, nicknames, and email addresses provided by that service. The core technical failure lies in the application's decision to mark these unescaped strings as html_safe without performing adequate sanitization or encoding checks. By explicitly marking this data as safe for HTML rendering, the framework bypasses its own automatic output escaping mechanisms, allowing raw malicious content embedded within legitimate-looking OAuth attributes to persist and execute within the context of other users' browsers.
The operational impact of this vulnerability is severe due to its stored nature combined with global sharing capabilities. An attacker who compromises an account or controls a valid OAuth identity can inject JavaScript payloads into their profile metadata during the authentication process. Because Huginn allows agents and connected services to be shared globally among team members, this malicious payload becomes persistent in the database rather than being transient like reflected XSS attacks. When any other user views these shared agents or attempts to attach them to their own workflows, the browser renders the page containing the injected script. This execution occurs within the security context of the victim's session, granting the attacker full access to the privileges associated with that user account.
The consequences extend beyond simple cookie theft or defacement. Since Huginn is a platform designed for automation and data processing, successful exploitation allows an adversary to exfiltrate sensitive credentials stored in agent configurations, steal active events containing potentially private business logic or personal data, and manipulate system behavior by executing arbitrary commands on behalf of the victim. If the targeted user holds administrative privileges, the attacker gains complete control over the Huginn instance, enabling them to modify global settings, access all shared agents across the organization, and further escalate their position within the infrastructure. This effectively compromises the confidentiality, integrity, and availability of the entire automation ecosystem managed by the platform.
From a classification perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. Specifically, it falls under stored XSS where malicious scripts are permanently stored within target servers. In terms of offensive security frameworks, this attack vector maps to the MITRE ATT&CK technique T1059, Command and Scripting Interpreter, specifically through browser-based execution via DOM manipulation or event handlers triggered by HTML rendering. The exploitation chain relies on social engineering aspects inherent in sharing agents globally, making it a high-risk issue that requires immediate attention from development teams responsible for input validation and output encoding practices within the application's helper modules.
To mitigate this vulnerability, developers must ensure that all user-supplied data originating from external OAuth providers is strictly escaped before being rendered in HTML templates. The use of html_safe should be reserved only for content that has been rigorously validated against a whitelist of safe characters or processed through robust sanitization libraries capable of stripping dangerous tags and attributes such as script, onerror, and onload handlers. Additionally implementing Content Security Policy headers can provide an additional layer of defense by restricting the sources from which scripts are allowed to execute, thereby limiting the impact even if some malicious content slips through initial validation checks. Regular security audits focusing on helper methods that handle dynamic user input are essential to prevent similar issues in other parts of the application architecture.