EUVD Vulnerability Catalog
EUVD-2026-67078
Severity: CRITICAL
Base Score: 10
CVSS Version: 4.0
Vulnerability Description
startServer.ts in the mcp-http-server package of UI-TARS-desktop defaulted its listen address to '::' when no host was given, so startSseAndStreamableHttpMcpServer bound the Streamable HTTP and SSE MCP transports to every interface, and its authentication middleware was optional: middlewares are applied only when a caller supplies them. The @agent-infra/mcp-server-commands and @agent-infra/mcp-server-filesystem entry points call startSseAndStreamableHttpMcpServer with a host and port alone and pass no middleware, so neither server required a credential. The commands server exposes a run_command tool that hands its caller-supplied command string to promisify(child_process.exec), so any unauthenticated client able to reach the port could run arbitrary commands as the user running the server, and the filesystem server exposed its file read and write tools on the same terms. The listen default became 127.0.0.1 in commit c2ad42e3eb9b27830db41a3e6f51ca7179d9b168; the package version stayed at 1.2.4 across that change, so the boundary is the commit rather than a release.
CVSS Vector Analysis
Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
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Attack Vector (AV): Network
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Attack Complexity (AC): Low
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Attack Requirements (AT): None
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Privileges Required (PR): None
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User Interaction (UI): None
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Vulnerability Confidentiality Impact (VC): High
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Vulnerability Integrity Impact (VI): High
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Vulnerability Availability Impact (VA): High
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Subsequent Confidentiality Impact (SC): High
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Subsequent Integrity Impact (SI): High
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Subsequent Availability Impact (SA): High
Affected Vendors & Systems
Vendor
bytedance
References & Advisory Links
- https://github.com/bytedance/UI-TARS-desktop/pull/1918
- https://github.com/bytedance/UI-TARS-desktop/commit/c2ad42e3eb9b27830db41a3e6f51ca7179d9b168
- https://github.com/bytedance/UI-TARS-desktop
- https://github.com/bytedance/UI-TARS-desktop/blob/e9f3387288da4af2ad99972da2ac916cdabce093/packages/agent-infra/mcp-http-server/src/startServer.ts#L263
- https://www.vulncheck.com/advisories/ui-tars-desktop-agent-infra-mcp-servers-bind-every-interface-without-authentication-exposing-arbitrary-command-execution
- https://nvd.nist.gov/vuln/detail/CVE-2026-81735
Metadata Profile
Database Authority
European Union Agency for Cybersecurity (ENISA) EUVD
Assigner
VulnCheck
EPSS Probability
0
Known Aliases
GHSA-p68p-fq8j-3639
CVE-2026-81735
Published On
2026-08-27
Last Updated
2026-08-27