Is CVE-2026-90819 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-90819 being exploited in the wild.

How severe is CVE-2026-90819?

High severity, with a CVSS score of 7.3, published 14 September 2026.

Is there a fix for CVE-2026-90819?

A patch was published on 2026-08-11: Patch 247a655043f145f6f8e3853724b6a543eaa02001 released; version 1.3.0 contains fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-90819 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-90819?

Check whether you run A2aproject A2a-Java at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-90819: a2aproject a2a-java HTTP response splitting in push notification headers

CVE-2026-90819 · Severity: high · CVSS 7.3 · Published 2026-09-14

The a2a-java SDK is a library used to implement the Agent2Agent protocol for secure agent communication. A vulnerability in the push notification header construction allows attackers to inject carriage return and line feed characters, enabling HTTP response splitting attacks that could be exploited to inject malicious content into responses, manipulate headers, or compromise application behavior.

Technologies: A2aproject A2a-Java. Vendors: A2aproject.

Quick answers

Is CVE-2026-90819 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-90819 being exploited in the wild.
How severe is CVE-2026-90819?: High severity, with a CVSS score of 7.3, published 14 September 2026.
Which products and versions are affected?: A2aproject A2a-Java 1.2.0.
Is there a fix for CVE-2026-90819?: A patch was published on 2026-08-11: Patch 247a655043f145f6f8e3853724b6a543eaa02001 released; version 1.3.0 contains fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-90819 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-90819?: Check whether you run A2aproject A2a-Java at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an HTTP response splitting issue (CWE-113) in the BasePushNotificationSender.dispatchNotification method of the server-common component. The root cause is insufficient validation of the Authorization header and X-A2A-Notification-Token values before they are included in HTTP responses, allowing attackers to inject CR/LF characters. The attack requires network reachability to a system using the vulnerable library and can be initiated without authentication. An attacker can exploit this to split HTTP responses, potentially injecting headers or content. The fix is available in version 1.3.0 and patch 247a655043f145f6f8e3853724b6a543eaa02001, which validates these header values before dispatch.

Affected products

a2aproject a2a-java 1.2.0

Timeline

2026-09-14: disclosed
2026-08-11: patched: Patch 247a655043f145f6f8e3853724b6a543eaa02001 released; version 1.3.0 contains fix

References

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