CVE-2026-77798 in Velociraptor
Summary
by MITRE • 09/24/2026
Velociraptor contains a deadlock condition that may be triggered by authenticated users. The issue stems from a lock management bug in the user management module.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified within Velociraptor represents a significant availability risk stemming from improper synchronization mechanisms in its authentication and user management subsystems. As an open-source digital forensics and incident response platform, Velociraptor relies heavily on concurrent access to shared resources for managing user sessions, permissions, and system state. The specific flaw involves a deadlock condition that can be induced by authenticated users who interact with the user management module under certain race conditions or sequential request patterns. This type of vulnerability is classified under CWE-833, which denotes Deadlock, indicating that two or more threads are blocked forever, waiting for each other to release resources they both need but cannot proceed because neither will relinquish its own lock.
From a technical perspective, the root cause lies in how locks are acquired and released during user management operations such as creating, modifying, or deleting users, or updating authentication tokens. If the application acquires multiple mutexes or read-write locks without adhering to a consistent global ordering protocol, it creates a scenario where Thread A holds Lock 1 and waits for Lock 2, while Thread B holds Lock 2 and waits for Lock 1. In the context of Velociraptor, this likely occurs when handling concurrent requests that modify user data structures which are protected by fine-grained locking mechanisms. Because the vulnerability is triggerable by authenticated users, an attacker who has valid credentials can deliberately craft a sequence of API calls or UI interactions to force these conflicting lock acquisitions, thereby causing the application threads responsible for processing those requests to hang indefinitely.
The operational impact of this deadlock is primarily centered on service availability and resource exhaustion. When the affected user management module enters a deadlocked state, it typically blocks not only the specific operations being performed by the malicious actor but may also stall dependent services that rely on the same underlying database connections or shared memory segments. This can lead to a denial-of-service condition for legitimate users attempting to access the Velociraptor interface or execute forensic queries. In severe cases, if the deadlock causes thread pool exhaustion within the Go runtime environment commonly used by such applications, it may necessitate an application restart to restore normal functionality, resulting in downtime and potential loss of real-time monitoring capabilities during incident response operations.
This vulnerability aligns with MITRE ATT&CK technique T1499, Endpoint Denial of Service, specifically under sub-techniques related to resource exhaustion or service disruption through software vulnerabilities. While the attacker requires authentication, which limits the attack surface compared to unauthenticated exploits, it remains a critical concern for internal threat actors or compromised accounts seeking to disrupt security operations centers that rely on Velociraptor for continuous monitoring and rapid response capabilities.
Mitigation strategies should focus on both immediate remediation and long-term architectural improvements. The primary fix involves correcting the lock ordering logic within the user management module to ensure that all code paths acquire locks in a consistent, predetermined order, thereby preventing circular wait conditions. Developers must also implement timeout mechanisms for lock acquisition so that if a deadlock is detected or approached, the operation fails gracefully rather than hanging indefinitely. Additionally, introducing more granular locking strategies or using concurrent data structures that minimize contention can reduce the window of opportunity for such race conditions. For administrators unable to immediately patch the software, restricting user privileges in the affected module and monitoring for high latency or thread blocking metrics can help detect potential exploitation attempts early. Regular code audits focusing on concurrency patterns are essential to prevent similar synchronization bugs from emerging in other parts of the application.