CVE-2026-111765

7.5High

Published 20 Oct 2026 · NVD status: Received · AI triage by gemini-3.8-flash

7.5High

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Impact: High impact on confidentiality
Weakness: CWE-522

Impact

Remote third-party servers can steal valid API keys or auth tokens via HTTP redirects. An attacker needs control over the initial endpoint or front-door routing to redirect client traffic to an untrusted authority.

Root cause

The synchronous POST client in AndroidA2AHttpClient overrides disabled redirects with a default followRedirects=true, causing OkHttp to forward custom auth headers (like X-API-Key and X-Auth-Token) to cross-authority redirect targets.

Affected systems

A2A Java SDK versions 1.3.0.Final through 1.3.1.Final

CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Fix & remediation

Upgrade A2A Java SDK to version 1.3.2.Final or later. As an interim workaround, explicitly configure followRedirects(false) on client HTTP requests.

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

Ad · In-content banner

NVD description

A2A Java SDK is the official Java SDK for the Agent2Agent (A2A) Protocol. Starting in version 1.3.0.Final and prior to version 1.3.2.Final, the AndroidA2AHttpClient synchronous POST path overrides the disabled-redirect setting in AndroidA2AHttpClient.createConnection() with the PostBuilder default followRedirects value of true, leaving a residual of the earlier credential-redirect fix. JSONRPCTransport and RestTransport add interceptor-produced authentication headers and call synchronous post() without disabling redirects. AuthInterceptor permits X-API-Key, API-Key, X-Auth-Token, and X-Authentication headers; Android's repackaged OkHttp strips Authorization on cross-authority redirects but retains these nonstandard headers, disclosing a complete configured API key or token to another authority. The additional exposure applies when redirect or front-door behavior is compromised separately from the credential-handling component, or those components operate in different trust domains; a completely malicious initial origin already receives the credential on the first request. Autonomous clients require no human action, while user-invoked workflows can require interaction. Explicit followRedirects(false) prevents the redirected request. The demonstrated impact is credential disclosure, not subsequent credential use, integrity or availability impact, code execution, or host compromise. This issue is fixed in version 1.3.2.Final.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-111765