CVE-2026-120314

Network-AI A2A task server fails open without a secret

Jovancoding · Network-AI A2AServer

First documented disclosure · Review checkpoint

Summary

An A2A server started without a secret accepts task operations without authentication.

Severity and exploitation evidence

Medium · 6.9/10 · CVSS 4.0. Severity source.

Exploitation not established: Controlled researcher evidence; the reviewed primary sources do not establish malicious exploitation or a confirmed victim.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

The Bearer-token check runs only when the optional secret is configured; startup previously allowed the absent-secret state.

Conditions required

An affected server is started without a secret and an attacker can reach it. Its default 127.0.0.1 bind limits network exposure; public reachability is deployment-dependent.

Potential impact

Unauthorized task submission, result retrieval and cancellation. Effects beyond task state depend on the application-supplied executor; arbitrary host code execution is not established by this report.

Affected versions and configurations

CNA: Network-AI 5.14.0 through 5.15.4. The original advisory only bounded the upper end because it had not established introduction.

Fix and mitigation status

5.15.5 requires a non-empty secret; intentionally unauthenticated development requires an explicit loopback-only opt-out.

Practical next steps

Upgrade and configure authentication before exposing A2A task routes. Verify both standalone startup and programmatic mounts; constrain the executor’s privileges.

Operating lesson

An optional credential must not silently turn an agent service into an unauthenticated task runner.

Evidence and limits

Public disclosure and release October 17; CNA November 2. The old body says unfixed, but the current package table, release and CNA establish 5.15.5. CNA Medium 6.9 CVSS 4.0 while its v3.1 and maintainer score are High 7.3; deployment prerequisites are retained.

Sources