CVE-2026-89292 in Mnestix
Summary
by MITRE • 11/03/2026
In Eclipse Mnestix Browser versions 1.6.0 up until but excluding 2.3.0 it was possible for an unauthenticated attacker to exfiltrate the MNESTIX_BACKEND_API_KEY for all configured Infrastructures.
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified in Eclipse Mnestix Browser, specifically affecting versions from 1.6.0 up to but excluding version 2.3.0, represents a critical security flaw that allows unauthenticated attackers to exfiltrate sensitive backend API keys associated with configured infrastructures. This issue stems from an improper restriction of access control on the application's internal endpoints or data handling mechanisms. In many modern web-based management consoles and browser extensions, configuration details such as authentication tokens are stored locally within the user profile or extension storage to facilitate seamless interaction with remote services without requiring repeated manual logins. When these sensitive credentials are not adequately protected against unauthorized retrieval by external scripts or malicious actors who have gained some level of access to the application's runtime environment, it creates a significant attack vector for credential theft and subsequent infrastructure compromise.
From a technical perspective, this flaw aligns with CWE-798: Use of Hard-coded Credentials, although in this context, it is more accurately described as CWE-200: Exposure of Sensitive Information to an Unauthorized Actor or potentially CWE-359: Exposure of Private Personal Information if the keys are tied directly to user identities. The core issue lies in how the Mnestix Browser handles its internal state and API key storage. If the application exposes these values through accessible JavaScript objects, local storage entries that lack proper permission checks, or via debug endpoints that remain enabled in production builds, any script running within the same context can read them. This is particularly dangerous because browser extensions often run with elevated privileges relative to standard web pages, meaning a malicious website could potentially exploit cross-site scripting vulnerabilities or other injection techniques to access these privileged data stores if the extension does not properly isolate its internal APIs from external scripts.
The operational impact of this vulnerability is severe due to the nature of the exposed asset: the MNESTIX_BACKEND_API_KEY. API keys serve as primary authentication mechanisms for communicating with backend services, often granting broad permissions such as reading sensitive telemetry data, modifying infrastructure configurations, or executing commands on managed nodes. An unauthenticated attacker who successfully retrieves these keys can impersonate legitimate users or systems within the Eclipse ecosystem. This leads to a complete bypass of authentication controls, allowing the adversary to perform actions that should require valid credentials. The attacker could potentially access confidential project data, disrupt service availability by altering configurations, or use the stolen keys as footholds for further lateral movement if those keys have broader permissions across multiple infrastructure environments configured within the browser profile.
This vulnerability maps directly to several techniques in the MITRE ATT&CK framework, most notably T1539: Steal Web Session Cookie and T1078: Valid Accounts, specifically under the sub-technique of stealing credentials from a local system or application storage. The attacker does not need to crack passwords or exploit complex logic flaws; they simply extract pre-existing valid authentication material. This simplifies the attack chain significantly, reducing the barrier to entry for malicious actors and increasing the likelihood of successful exploitation in environments where users may have multiple infrastructures configured with varying levels of sensitivity.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary fix involves upgrading Eclipse Mnestix Browser to version 2.3.0 or later, as this release explicitly addresses the access control issues that allowed for unauthorized key retrieval. For organizations unable to upgrade immediately, it is critical to rotate all affected API keys across all configured infrastructures to invalidate any potentially exfiltrated credentials. Additionally, developers should review how sensitive data is stored within browser extensions and web applications, ensuring that such information is encrypted at rest or accessed only through strictly controlled internal APIs that verify the origin of requests. Implementing Content Security Policy directives that restrict access to extension internals from external contexts can also help prevent script-based exfiltration attempts in future versions.