1mcp agent up to 0.39.0 improper authorization

Summaryinfo

A vulnerability categorized as critical has been discovered in 1mcp agent up to 0.39.0. This affects an unknown part. Executing a manipulation can lead to improper authorization. This vulnerability is tracked as CVE-2026-108586. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in 1mcp agent up to 0.39.0. This vulnerability affects an unknown functionality. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

1MCP Agent (@1mcp/agent) 0.20.0 through 0.39.0 contains an incorrect authorization vulnerability that allows authenticated clients to bypass OAuth tag-scope enforcement using negated advanced tag-filter expressions. Attackers holding a single-tag token can send a filter like not <granted-tag> to list and invoke tools on backend MCP servers outside their granted scopes.

The advisory is available at hackmd.io. This vulnerability was named CVE-2026-108586 since 10/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/10/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-96373). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• 1mcp

Name

• agent

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39.0

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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