CVE-2026-81735UI-TARS-desktop @agent-infra MCP Servers Bind Every Interface Without Authentication, Exposing Arbitrary Command Execution
Updated under an hour ago ()
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It affects bytedance UI-TARS-desktop. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-306
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Deferred
- Record last updated
- Sep 24, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
bytedance UI-TARS-desktop bytedance:ui_tars_desktop (from the name) | c2ad42e3eb9b27830db41a3e6f51ca7179d9b168 not affected; before c2ad42e3eb9b27830db41a3e6f51ca7179d9b168 | CNA record |
References
- https://github.com/bytedance/UI-TARS-desktop/pull/1918issue-tracking, patch
- https://github.com/bytedance/UI-TARS-desktop/commit/c2ad42e3eb9b27830db41a3e6f51ca7179d9b168patch
- https://github.com/bytedance/UI-TARS-desktopproduct
- https://github.com/bytedance/UI-TARS-desktop/blob/e9f3387288da4af2ad99972da2ac916cdabce093/packages/agent-infra/mcp-http-server/src/startServer.ts#L263technical-description
- https://www.vulncheck.com/advisories/ui-tars-desktop-agent-infra-mcp-servers-bind-every-interface-without-authentication-exposing-arbitrary-command-executionthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.