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CVE-2026-108586— 1MCP Agent 0.20.0 through 0.39.0 OAuth Tag-Scope Bypass via Negated Tag Filter

Quick assessment

Affected
1mcp-app @1mcp/agent
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

1MCP Agent（@1mcp/agent）版本 0.20.0 至 0.39.0 存在一个不正确的授权漏洞，该漏洞允许已认证客户端通过使用否定型高级标签过滤器表达式，绕过 OAuth 标签范围（tag-scope）的执行检查。拥有单标签令牌的攻击者可以发送类似 “not <granted-tag>” 的过滤器，从而列出并调用后端 MCP 服务器上超出其已授权范围的工具。

CVSS 5.4 · Medium EPSS 0.19% · P8

Affected Version Matrix 1

VendorProduct Version RangeStatus
1mcp-app @1mcp/agent 0.20.0≤ 0.39.0 affected
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I. Basic Information for CVE-2026-108586

Vulnerability Information
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Vulnerability Title
1MCP Agent 0.20.0 through 0.39.0 OAuth Tag-Scope Bypass via Negated Tag Filter
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
授权机制不正确
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
1mcp-app @1mcp/agent 0.20.0 ~ 0.39.0 -

II. Public POCs for CVE-2026-108586

# POC Description Source Link Shenlong Link
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III. Intelligence Information for CVE-2026-108586

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Patches & Fixes for CVE-2026-108586 (2)

Vendor Advisories for CVE-2026-108586 (1)

Security Blog Posts for CVE-2026-108586 (1)

IV. Related Vulnerabilities

Same weakness: CWE-863

V. Comments for CVE-2026-108586

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