Secuno
ENNL
Book demo

CVE-2026-81735

Authentication bypass

10.0 CRITICALEPSS 0.78%
  1. Published27 Aug 2026

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 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-876899.8
The Metasploit Framework Web Service REST API (msf-ws) exposes the credential store…
CVE-2026-843138.8
Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, POST…
CVE-2026-1095759.8
In HAProxy Data Plane API 2.2.0 through 3.4.3 (and corresponding Enterprise Edition…
CVE-2026-571189.8
PraisonAI is a multi-agent teams system. Prior to praisonaiagents 1.6.59,…
CVE-2026-1093718.2
ZITADEL 3.0.0 before 4.18.0 contains a missing authentication vulnerability in the…
CVE-2026-1085498.1
cc-connect through 1.5.0 contains a missing authentication vulnerability in the MAX…

Frequently asked

Is CVE-2026-81735 being actively exploited?

CVE-2026-81735 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.78%.

How severe is CVE-2026-81735?

CVE-2026-81735 has a CVSS 3.1 base score of 10.0, rated critical. EPSS estimates a 0.78% probability of exploitation.

How do I fix CVE-2026-81735?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-81735 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.