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CVE-2026-111761— A2A Java SDK has Server-Side Request Forgery (SSRF) in push-notification delivery

Quick assessment

Affected
a2aproject a2a-java
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

A2A Java SDK 是 Agent2Agent（A2A）协议的官方 Java 软件开发工具包。在 1.3.0.Final 版本之前，server-common 模块中的 BasePushNotificationSender 在将任务数据发送至 TaskPushNotificationConfig 中指定的 URL 时，未对目标地址进行验证，未限制协议方案（scheme），也未对重定向次数进行限制。InMemoryPushNotificationConfigStore.setInfo 方法会原样存储该 URL，

CVSS 5.8 · Medium
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I. Basic Information for CVE-2026-111761

Vulnerability Information
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Vulnerability Title
A2A Java SDK has Server-Side Request Forgery (SSRF) in push-notification delivery
Source: CVE Program / CVE List V5
Vulnerability Description
A2A Java SDK is the official Java SDK for the Agent2Agent (A2A) Protocol. Prior to 1.3.0.Final, BasePushNotificationSender in server-common sends task data to the URL in TaskPushNotificationConfig without destination validation, scheme restrictions, or bounds on redirects. InMemoryPushNotificationConfigStore.setInfo stores the URL verbatim, and onCreateTaskPushNotificationConfig does not validate the destination. In the default deployment with push notifications enabled, an unauthenticated caller can register a destination through an inline SendMessage configuration or CreateTaskPushNotificationConfig for an existing task, causing task status and artifact updates to send requests from the server's network position to loopback, private, link-local cloud-metadata, IPv6 unique-local, unspecified, or multicast destinations where routing permits. JdkA2AHttpClient and VertxA2AHttpClient follow redirects, allowing a webhook redirect to bypass creation-time destination checks and convert a POST into a GET; hostname-only checks also do not prevent DNS rebinding. Direct POST delivery can push attacker-influenced task data into internal services, whereas a redirected POST-to-GET request drops the body. The sender discards the fetched response and does not expose delivery success or failure, so the demonstrated behavior does not provide response read-back. No credentials or user interaction are required. This issue is fixed in version 1.3.0.Final.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
服务端请求伪造(SSRF)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
a2aproject a2a-java < 1.3.0.Final -

II. Public POCs for CVE-2026-111761

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III. Intelligence Information for CVE-2026-111761

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Vendor Pages for CVE-2026-111761 (1)

Other References for CVE-2026-111761 (3)

Same Patch Batch · a2aproject · 2026-10-20 · 5 CVEs total

CVE-2026-111765 7.5 HIGH A2A Java SDK: Android synchronous POST forwards credentials across authorities after incom
CVE-2026-111764 7.5 HIGH A2A Java SDK has a fail-open default task authorization
CVE-2026-111762 5.7 MEDIUM A2A Java SDK: Push notification credentials logged in cleartext on protobuf parse failure
CVE-2026-111763 5.7 MEDIUM A2A Java SDK send client credentials under server-controlled HTTP header name, enabling le

IV. Related Vulnerabilities

Same product: a2a-java
Same vendor: a2aproject
Same weakness: CWE-918

V. Comments for CVE-2026-111761

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