CVE-2026-111761 · GHSA-q78c-5jjq-57g8
A2A Java SDK has Server-Side Request Forgery (SSRF) in push-notification delivery
- Risk score
- 48/100
- CVSS
- 5.8 v3.1
- Exploit chance (30 days)
- 0.5%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 s…
- Affected
- org.a2aproject.sdk:a2a-java-sdk-server-common (maven) < 1.3.0.Final
- Fix
- Upgrade org.a2aproject.sdk:a2a-java-sdk-server-common to 1.3.0.Final or later.
- Exploitation
- No known exploitation
Story map
At a glance
org.a2aproject.sdk:a2a-java-sdk-server-common: Amber, patch this week. A2A Java SDK is the official Java SDK for the Agent2Agent (A2A) Protocol. Prior to 1.3.0.Final, the default InMemoryTaskStore configuration performs no authorization on task reads: the no-argument constructor sets authorizationProvider to null, and InMemoryTaskStore.get(String taskId) returns the stored task without c…
The flaws
- CVE-2026-111761: A2A Java SDK has Server-Side Request Forgery (SSRF) in push-notification delivery (CVSS 5.8 · EPSS 1%)
- CVE-2026-111764: A2A Java SDK has a fail-open default task authorization (CVSS 7.5 · EPSS 1%)
The fix
Upgrade org.a2aproject.sdk:a2a-java-sdk-server-common: 1.3.0 or later on your release line
Who is exposed: org.a2aproject.sdk:a2a-java-sdk-server-common (maven) < 1.3.0.Final
Where it stands
- No known exploitation
Connects to
- Same weakness: Server-side request forgery (CWE-918). 220 other warnings in 30 days
Why it is Yellow
- CVSS 5.8 medium
- On your watchlist: Maven
Affected packages
| Package | Ecosystem | Vulnerable | Fixed in |
|---|---|---|---|
| org.a2aproject.sdk:a2a-java-sdk-server-common | maven | < 1.3.0.Final | 1.3.0.Final |
References
- https://github.com/advisories/GHSA-q78c-5jjq-57g8
- https://github.com/a2aproject/a2a-java/security/advisories/GHSA-q78c-5jjq-57g8
- https://nvd.nist.gov/vuln/detail/CVE-2026-111761
- https://github.com/a2aproject/a2a-java/pull/1096
- https://github.com/a2aproject/a2a-java/commit/b855b2ae37e4bf23f73e7746ce166fbc5a0b8b5b
- https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final
- https://github.com/advisories/GHSA-q78c-5jjq-57g8
Original 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.
Last activity 20 Oct 2026. Patch Forecast updates every hour.