CVE-2026-111057: Mercury Unauthenticated Remote Code Execution via API Terminals Access Control Bypass
Summary
CVE-2026-111057: Mercury: Unauthenticated Remote Code Execution in /api/terminals - access control bypass. Affects mercury versions >= 3.0.0, < 3.2.4. Fixed in 3.2.4. How to fix ↓
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Background
Mercury is an open-source application designed to facilitate interactive computing environments, particularly for JupyterLab users. It allows users to manage notebooks, execute code, and interact with various data sources. However, a critical vulnerability has been identified that allows unauthenticated users to gain unauthorized access to the system's terminal API, potentially leading to severe security breaches.
Vulnerability Detail
The vulnerability arises from a missing comma in the BLOCKED_PATTERNS list within the mercury_app/block_handler.py file. This omission causes the blocklist to fail to effectively cover the /api/terminals endpoint, allowing any unauthenticated attacker to spawn a full, interactive OS-level shell on the host running Mercury. The implications of this vulnerability are severe, as it grants attackers full read and write access to the system, enabling them to manipulate files, access sensitive data, and potentially compromise the entire server.
How To Fix
Latest published version: 3.2.11 as of 22 Oct 2026
pip install --upgrade "mercury==3.2.11"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
3.2.4
This is the first release that contains the fix.
pip install --upgrade "mercury==3.2.4"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, restrict access to the Mercury server by implementing network-level controls such as firewalls or VPNs to prevent unauthorized access until the patch is applied.
Conclusion
The CVE-2026-111057 vulnerability in Mercury poses a significant risk due to its potential for unauthenticated remote code execution. It is crucial for users to update their installations and apply the necessary fixes to safeguard their systems.
See every vulnerability recorded for mercury →
FAQ
CVE-2026-111057 is a critical vulnerability in the Mercury application that allows unauthenticated remote code execution via the /api/terminals endpoint due to an access control bypass.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
The vulnerability can lead to full read and write access to the system, allowing attackers to modify files, access sensitive data, and potentially take control of the server.
To fix the vulnerability, update Mercury to version 3.2.4 or later and ensure the BLOCKED_PATTERNS list is correctly formatted in the mercury_app/block_handler.py file.
The CVSS score of this vulnerability is 10.0, indicating a critical level of severity.
References
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