CVE-2026-18998
Received Received - Intake

Improper Authorization in Mercury Agent up to 1.1.12

Publication date: 2026-08-06

Last updated on: 2026-08-06

Assigner: VulDB

Description
A vulnerability was determined in cosmicstack-labs mercury-agent up to 1.1.12. Impacted is the function SubAgent.run of the file src/core/sub-agent.ts of the component delegate_task Tool. Executing a manipulation can lead to improper authorization. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

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Meta Information

Published
2026-08-06
Last Modified
2026-08-06
Generated
2026-08-06
AI Q&A
2026-08-06
EPSS Evaluated
N/A
NVD
CVE-2026-18998
EUVD
EUVD-2026-53712

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
cosmicstack-labs mercury-agent to 1.1.12 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-266 A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.
CWE-285 The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.

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Executive Summary

This vulnerability is an improper authorization issue in cosmicstack-labs mercury-agent up to version 1.1.12. It allows restricted sub-agents to bypass intended tool restrictions and perform unauthorized actions. The allowedTools constraint is not enforced at runtime, letting sub-agents access tools they should not have, such as list_agents and stop_agent.

Detection Guidance

Check if cosmicstack-labs mercury-agent versions up to 1.1.12 are installed by running: npm list @cosmicstack/mercury-agent. Inspect the SubAgent.run function in src/core/sub-agent.ts for improper enforcement of allowedTools constraints.

Impact Analysis

An attacker could exploit this to delegate a task with restricted tools but gain access to unauthorized tools via the Web Dashboard chat interface. This allows halting sibling agents, interfering with parallel task execution, and violating privilege boundaries.

Compliance Impact

This vulnerability could lead to unauthorized access or actions by restricted sub-agents, potentially violating data protection requirements under GDPR or HIPAA. Improper authorization may result in unauthorized data exposure or system interference, compromising compliance with these regulations.

Mitigation Strategies

Upgrade mercury-agent to a version beyond 1.1.12 if available. If not, restrict access to the Mercury Agent Web Dashboard chat interface and review tool delegation policies to prevent unauthorized tool usage.

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