External risk intelligence

MemOS Authentication Bypass Leads to Full API Access

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-75110

MemOS is an LLM/AI agent platform with API endpoints. These services are commonly deployed as network-accessible web or API services intended for integration or user interaction. The vulnerability directly affects the authentication middleware governing these reachable API management endpoints, making them likely to be exposed in standard deployment scenarios.

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns a vulnerability in MemOS, a memory operating system designed for LLMs and AI agents. When authentication is enabled but a specific environment variable is unset, the system may incorrectly trust unauthenticated requests, allowing unauthorized access to administrative functions and data. The main concern is confirming relevance and exposure.

Unauthenticated access to AI system functions.
Allows broad administrative control and data access.
Verify if your AI deployments are impacted.

Attack Path

How an attacker could exploit the issue

An unauthenticated remote attacker can exploit a misconfiguration in MemOS when authentication is enabled but a specific secret is not set. This allows the attacker to bypass access controls, gain full administrative privileges, and access all data.

Network access required.
Authentication bypass.
Full administrative compromise.

Live Threat

Current exploitation, exposure, and threat context

When MemOS is deployed with authentication enabled but the `INTERNAL_SERVICE_SECRET` environment variable is not set, unauthenticated attackers can bypass access controls. This allows them to access administrative functions and all data endpoints as if they were a trusted internal principal.

Access to sensitive API keys.
Bypass authentication checks remotely.
Compromise all system data.

Operational Fix

Recommended remediation, mitigation, and detection steps

In environments where MemOS is deployed with authentication enabled but the `INTERNAL_SERVICE_SECRET` is not configured, an unauthenticated remote attacker can bypass authentication. This allows them to gain full administrative and data access through the API endpoints. The first step is to identify MemOS instances, confirm their reachability and business criticality, locate the accountable owner, and then plan remediation based on the assessed risk.

Identify MemOS instances and owners.
Verify `INTERNAL_SERVICE_SECRET` configuration.
Plan remediation based on exposure.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is MemOS?

MemOS is a specialized memory operating system built to support LLMs and AI agents. It functions as a platform for managing data and AI-driven interactions. Developers use it to organize information and execute agentic tasks, often deploying it as a networked service to handle API requests and integrations.

What is the vulnerability in CVE-2026-75110?

This vulnerability is an authentication bypass involving a comparison error, classified as CWE-697. It occurs because the system mistakenly compares two undefined values as equal. When a required internal security secret is not defined, the middleware incorrectly assumes a request is trusted, granting full administrative privileges to anyone who sends a request.

How does an attacker trigger this authentication bypass?

An attacker triggers the bug by sending a network request to the system when the INTERNAL_SERVICE_SECRET environment variable is missing. It is important to note that if this secret variable is correctly configured, the bypass does not occur. The flaw specifically relies on the code's failure to handle the empty state of that variable.

Do I need to worry if my MemOS instance is internal?

According to Halo Surface Signal, you should be concerned because MemOS services are frequently deployed as network-accessible APIs. Even if you consider a service internal, any path that allows external network connectivity creates a potential window for exploitation. Verify your deployment environment to see if your API endpoints are reachable from outside your trusted network perimeter.

What should I do first to secure my MemOS deployment?

Start by confirming your current configuration for the INTERNAL_SERVICE_SECRET environment variable. Identify all running instances of MemOS and determine who is responsible for their maintenance. If the variable is unset, prioritize securing the instance immediately and verify that access controls are properly enforced.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.