CVE-2026-119660 in MuseBot
Summary
by MITRE • 10/30/2026
MuseBot before 2.0.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge admin sessions by using the hard-coded default session_key 'muse_bot_session_key'. Attackers can sign a MuseBot-session cookie carrying a user_id to gain full administrative access, reading password hashes, chat records, and bot configuration, and stopping bots.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified in versions of MuseBot prior to 2.0.0 represents a critical authentication bypass flaw rooted in the improper handling of session management credentials. Specifically, the application utilizes a hard-coded default value for its session signing key, designated as 'muse_bot_session_key'. In secure software architecture, cryptographic keys used for signing and verifying sessions must be unique per deployment, randomly generated, and kept confidential to prevent unauthorized parties from forging valid authentication tokens. By embedding this static secret directly into the source code or configuration without allowing for customization during installation, the developers have created a predictable vector that any external actor can exploit with minimal effort. This design failure fundamentally undermines the integrity of the session-based access control mechanism, as it removes the secrecy required to ensure that only legitimate server-generated sessions are accepted by the application logic.
From a technical perspective, this flaw allows unauthenticated attackers to forge administrative session cookies through cryptographic signature manipulation. Since the signing key is publicly known or easily discoverable due to its default nature and common placement in source repositories, an attacker can construct a malicious cookie payload containing any desired user identifier, such as that of an administrator account. By applying the known 'muse_bot_session_key' to sign this forged token, the resulting session cookie will pass all server-side verification checks because it is cryptographically valid according to the application's logic. This process effectively bypasses the authentication layer entirely, granting the attacker full administrative privileges without needing valid credentials for any existing user account. The ease of exploitation means that automated scanning tools and script kiddies can rapidly identify and compromise instances running these vulnerable versions across the internet.
The operational impact of this vulnerability is severe, leading to a complete loss of confidentiality, integrity, and availability within the affected system. Once an attacker gains administrative access through forged sessions, they possess unrestricted control over the bot's functionality and underlying data stores. This includes the ability to read sensitive information such as password hashes stored in the database, which can be further cracked offline to compromise user accounts across multiple platforms if weak hashing algorithms are employed. Additionally, attackers can exfiltrate private chat records, violating privacy regulations and exposing users to social engineering or blackmail risks. The attacker also gains the capability to modify bot configurations, potentially altering command behaviors or integrating malicious external services. Furthermore, the ability to stop bots disrupts service availability for legitimate users, causing operational downtime and potential reputational damage for the administrators managing these automated systems.
This vulnerability aligns with CWE-798: Use of Hard-coded Credentials, as it involves the use of a static password or key that is hardcoded into the application code rather than being generated dynamically per instance. It also relates to CWE-613: Insufficient Session Expiration, insofar as forged sessions remain valid until manually invalidated by an administrator who may be unaware of the compromise. In terms of offensive security frameworks, this exploitation technique maps directly to MITRE ATT&CK Tactic TA0004 (Privilege Escalation) and specifically Technique T1528: Steal Application Access Token, where attackers abuse application-level tokens to gain unauthorized access. The scenario also touches upon T1078: Valid Accounts, as the attacker impersonates a valid administrative account through token forgery rather than credential theft.
To mitigate this vulnerability, immediate action is required for all systems running MuseBot versions before 2.0.0. Administrators should upgrade to version 2.0.0 or later, where the session key management has presumably been corrected to use dynamic generation and secure storage mechanisms such as environment variables rather than hard-coded strings. For organizations unable to patch immediately due to dependency constraints, a temporary mitigation involves manually overriding the default configuration if supported by the deployment method, ensuring that a strong, randomly generated secret is used for session signing instead of 'muse_bot_session_key'. Additionally, implementing strict input validation and monitoring logs for unusual authentication patterns or high-frequency access from single IP addresses can help detect ongoing exploitation attempts. Regular security audits focusing on credential management practices are essential to prevent similar hard-coded secrets in future development cycles, ensuring that sensitive cryptographic material is never exposed in source code repositories or default configurations.