A2A Java SDK: Android synchronous POST forwards credentials across authorities after incomplete redirect fix

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-111765: 0.80% estimated exploitation activity in the next 30 days; percentile 56.75 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The GHSA-9rhm fix added this safe setting in AndroidA2AHttpClient.createConnection(): connection.setInstanceFollowRedirects(false); The synchronous POST builder later overwrites it: private boolean followRedirects = true; public A2AHttpResponse post() throws IOException { HttpURLConnection connection = createConnection("POST", false); connection.setInstanceFollowRedirects(followRedirects); // ... } The second assignment wins. JSONRPCTransport and RestTransport both add interceptor-produced headers and call synchronous post() without setting followRedirects(false). On Android's repackaged OkHttp implementation, a cross-authority redirect strips Authorization but retains nonstandard request headers. AuthInterceptor permits four nonstandard authentication header names: X-API-Key API-Key X-Auth-Token X-Authentication I confirmed that the exact v1.3.1.Final Maven artifact forwards complete synthetic values under all four names to a second loopback authority. I also reproduced the…

Published by the source

20 Oct 2026, 21:08 UTC

Last modified by the source

21 Oct 2026, 03:11 UTC

Source last checked

26 Oct 2026, 16:58 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4fpj-g9jf-9rgg

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-4fpj-g9jf-9rgg

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# Patch Next advisory brief: CVE-2026-111765

Advisory: A2A Java SDK: Android synchronous POST forwards credentials across authorities after incomplete redirect fix
IDs: CVE-2026-111765, GHSA-4fpj-g9jf-9rgg
Record: https://patchnext.com/advisories/cve-2026-111765 (revision 2, source checked 26 Oct 2026, 16:58 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.a2aproject.sdk:a2a-java-sdk-http-client-android 1.3.2.Final. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.a2aproject.sdk:a2a-java-sdk-http-client-android: affected >= 1.3.0.Final, <= 1.3.1.Final; fixed in 1.3.2.Final

## Suggested inspection (read-only)
- Maven org.a2aproject.sdk:a2a-java-sdk-http-client-android: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.a2aproject.sdk:a2a-java-sdk-http-client-android.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-4fpj-g9jf-9rgg (OSV record GHSA-4fpj-g9jf-9rgg lists affected ranges: Maven org.a2aproject.sdk:a2a-java-sdk-http-client-android >=1.3.0.Final <1.3.2.Final (fixed))
- Verified: https://github.com/advisories/GHSA-4fpj-g9jf-9rgg (GitHub-reviewed advisory GHSA-4fpj-g9jf-9rgg lists affected ranges: Maven org.a2aproject.sdk:a2a-java-sdk-http-client-android >=1.3.0.Final <=1.3.1.Final)

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