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TI-2026-76905 Aliases CVE-2026-111765GHSA-4fpj-g9jf-9rgg

Android A2A Java SDK forwards API keys across redirects

Priority HIGH 72CWE-522Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-522.

Summary

The Android HTTP client in the A2A Java SDK from 1.3.0.Final before 1.3.2.Final follows redirects on synchronous POST requests even when they are disabled. Android's OkHttp strips Authorization on cross-authority redirects but keeps the X-API-Key and similar headers, disclosing the configured key or token (CWE-522). An attacker who controls a redirect separately from the credential handling can read the credential, and the impact is limited to disclosure.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00803 56th percentileScored 2026-11-07
Fix Fixed a2a-java (a2aproject): 1.3.2.Finalorg.a2aproject.sdk:a2a-java-sdk-http-client-android (Maven): 1.3.2.Final

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
a2aprojecta2a-java1.3.0.Final to before 1.3.2.Final1.3.2.FinalPatch availableCNA
—org.a2aproject.sdk:a2a-java-sdk-http-client-android (Maven)1.3.0.Final to before 1.3.2.Final1.3.2.FinalPatch availableGHSA-4fpj-g9jf-9rgg
  • a2a-java Vendora2aproject Affected 1.3.0.Final to before 1.3.2.Final Fixed in 1.3.2.Final Patch available CNA
  • org.a2aproject.sdk:a2a-java-sdk-http-client-android (Maven) Vendor— Affected 1.3.0.Final to before 1.3.2.Final Fixed in 1.3.2.Final Patch available GHSA-4fpj-g9jf-9rgg

Remediation

Update the org.a2aproject.sdk:a2a-java-sdk-http-client-android package to 1.3.2.Final, which fixes this issue. The sources list no fixed version for a2a-java. Setting followRedirects(false) prevents the redirected request.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA a2a-java (a2aproject) Fixed in 1.3.2.Final
  • Fix · GHSA-4fpj-g9jf-9rgg org.a2aproject.sdk:a2a-java-sdk-http-client-android (Maven) Fixed in 1.3.2.Final Advisory →

Timeline

  1. 2026-10-20 Threatist record created from CVE-2026-111765
  2. 2026-10-21 Alias added: GHSA-4fpj-g9jf-9rgg
  3. 2026-10-21 Fix available: Maven/org.a2aproject.sdk:[email protected] · GHSA-4fpj-g9jf-9rgg
  4. 2026-10-21 CVSS score added · GHSA-4fpj-g9jf-9rgg
  5. 2026-10-21 Weakness changed · GHSA-4fpj-g9jf-9rgg
  6. 2026-10-21 9 new references · GHSA-4fpj-g9jf-9rgg
  7. 2026-10-22 Priority changed: MEDIUM → LOW
  8. 2026-10-23 CISA SSVC decision points changed
  9. 2026-10-23 Priority changed: LOW → HIGH

References

Advisory 1

Other 8

  • TI-2026-76904 A2A Java SDK default task store skips authorization on task reads CVSS 3.1HIGH 7.5
  • TI-2026-76847 Server-side request forgery in A2A Java SDK push notifications CVSS 3.1MEDIUM 5.8
  • TI-2026-81183 Resource consumption in a2aproject a2a-go REST SSE handler CVSS 4.0MEDIUM 6.9
  • TI-2026-61722 HTTP response splitting in a2aproject a2a-java CVSS 4.0MEDIUM 6.9
  • TI-2026-81185 Denial of service in a2aproject a2a-go Distributed Manager Cancel CVSS 4.0MEDIUM 6.9
  • TI-2026-80567 Error message leaks sensitive information in a2a-go CreateExecutor CVSS 4.0MEDIUM 6.9
See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences