CVE-2026-81735

CRITICALPre-NVD 10.010.0—
EchelonGraph scoreHIGH confidence

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-27. the CNA's CVSS baseline 10.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 4 sources updated this week
10.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 10.0Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
10.0
EG Score
10.0(high)
EG Risk
50(Track)
EG Risk 50/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity100% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 29, 2026

Advisory Details (5)

Auto-updated Aug 29, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic

UI-TARS-desktop @agent-infra MCP Servers Bind Every Interface Without Authentication, Exposing Arbitrary Command Execution | Advisories | VulnCheck

https://www.vulncheck.com/advisories/ui-tars-desktop-agent-infra-mcp-servers-bind-every-interface-without-authentication-exposing-arbitrary-command-execution
generic

UI-TARS-desktop/packages/agent-infra/mcp-http-server/src/startServer.ts at e9f3387288da4af2ad99972da2ac916cdabce093 · bytedance/UI-TARS-desktop · GitHub

https://github.com/bytedance/UI-TARS-desktop/blob/e9f3387288da4af2ad99972da2ac916cdabce093/packages/agent-infra/mcp-http-server/src/startServer.ts#L263
generic

GitHub - bytedance/UI-TARS-desktop: The Open-Source Multimodal AI Agent Stack: Connecting Cutting-Edge AI Models and Agent Infra · GitHub

https://github.com/bytedance/UI-TARS-desktop
github_commit

commit c2ad42e3eb9b (bytedance/UI-TARS-desktop)

Fix landed in bytedance/UI-TARS-desktop commit c2ad42e3eb9b — awaiting tagged release

https://github.com/bytedance/UI-TARS-desktop/commit/c2ad42e3eb9b27830db41a3e6f51ca7179d9b168
github_pr

fix(mcp-http-server): default host to 127.0.0.1, not all interfaces

Fix merged in bytedance/UI-TARS-desktop PR #1918 on 2026-07-01 — awaiting tagged release

https://github.com/bytedance/UI-TARS-desktop/pull/1918

Vendor Advisories for CVE-2026-81735(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 25× in last 7d / 25× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 02:29 UTCEG score recompute
  2. 2026-08-30 02:29 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 22:53 UTCGHSA enrichment
  5. 2026-08-29 19:15 UTCGHSA enrichment
  6. 2026-08-29 15:37 UTCGHSA enrichment
  7. 2026-08-29 11:59 UTCEG score recompute
  8. 2026-08-29 11:58 UTCGHSA enrichment
  9. 2026-08-29 10:53 UTCGHSA enrichment
  10. 2026-08-29 07:11 UTCGHSA enrichment
  11. 2026-08-29 03:33 UTCGHSA enrichment
  12. 2026-08-28 23:53 UTCEG score recompute
  13. 2026-08-28 23:53 UTCGHSA enrichment
  14. 2026-08-28 21:42 UTCEPSS rescore
  15. 2026-08-28 19:22 UTCGHSA enrichment
  16. 2026-08-28 15:23 UTCGHSA enrichment
  17. 2026-08-28 11:40 UTCGHSA enrichment
  18. 2026-08-28 08:03 UTCGHSA enrichment
  19. 2026-08-28 04:23 UTCGHSA enrichment
  20. 2026-08-28 00:44 UTCGHSA enrichment
  21. 2026-08-27 21:01 UTCEG score recompute
  22. 2026-08-27 21:01 UTCGHSA enrichment
  23. 2026-08-27 17:24 UTCEG score recompute
  24. 2026-08-27 16:47 UTCEG score recompute
  25. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81735?
CVE-2026-81735 is a critical vulnerability published on August 27, 2026. 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…
When was CVE-2026-81735 disclosed?
CVE-2026-81735 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81735 actively exploited?
CVE-2026-81735 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.2% of all scored CVEs.
What is the CVSS score of CVE-2026-81735?
CVE-2026-81735 has a CVSS v4.0 base score of 10.0 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-81735?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81735, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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