CVE-2026-62863— MoLing: unauthenticated SSE and wildcard CORS expose tool sessions

Quick assessment

Affected

gojue moling

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.

MoLing 是一款基于计算机操作和浏览器操作的 MCP（Model Context Protocol）服务器。在 0.5.0 版本之前，当 MoLing 通过参数以 SSE（Server-Sent Events）模式运行时，其和 HTTP 端点未对请求进行身份验证，且其依赖的库将响应头设置为。攻击者可以构造恶意网页，利用跨域连接至端点（包含回环监听器），读取事件以获取。一旦受害者在 SSE 模式下访问该恶意页面，攻击者即可利用泄露的向端点发送未经授权的 MCP 工具调用。根据所配置的工具，这

CVSS 9.6 · Critical Updated Oct 31, 2026

Possible ATT&CK Techniques 3 AI

T1083 · File and Directory Discovery T1059 · Command and Scripting Interpreter T1190 · Exploit Public-Facing Application

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Vulnerability Information

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Vulnerability Title

MoLing: unauthenticated SSE and wildcard CORS expose tool sessions

Source: CVE Program / CVE List V5

Vulnerability Description

MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using `-l`, its `/sse` and `/message` HTTP endpoints do not authenticate requests and the `mcp-go` dependency sets `Access-Control-Allow-Origin: *`. A malicious web page can open a cross-origin `EventSource` to `/sse`, including a loopback listener, and read the `endpoint` event to obtain `sessionId`. After a victim running SSE mode visits that page, the attacker can use the disclosed `sessionId` against `/message` to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

Source: CVE Program / CVE List V5

Vulnerability Type

过度许可的跨域白名单

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
gojue	moling	< 0.5.0	-

II. Public POCs for CVE-2026-62863

#	POC Description	Source Link	Shenlong Link

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No public POC found.

III. Intelligence Information for CVE-2026-62863

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Patches & Fixes for CVE-2026-62863 (2)

Vendor Advisories for CVE-2026-62863 (1)

🔗 SSE mode exposes unauthenticated endpoint with CORS wildcard, leaking sessionId to cross-origin attackers · Advisory · gojue/moling · GitHub Read full article x_refsource_CONFIRM

Vendor Pages for CVE-2026-62863 (1)

🔗 Release v0.5.0 · gojue/moling · GitHub x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-62863

IV. Related Vulnerabilities

Same weakness: CWE-942