CVE-2026-90820 Missing authorization in a2a-java
Remote attackers can bypass authorization checks in the onListTasks function to access task data without proper permissions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90820?
CVE-2026-90820 is a medium-severity missing authorization vulnerability in a2aproject a2a-java, published on 14 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A security vulnerability has been detected in a2aproject a2a-java 1.2.0. The impacted element is the function AuthorizationRequestHandlerDecorator.onListTasks of the file server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/AuthorizationRequestHandlerDecorator.java. Such manipulation leads to missing authorization. The attack can be launched remotely. Upgrading to version 1.3.0 is sufficient to resolve this issue. The name of the patch is e9a1abf9c90c02b16d17293afdc3cc2f555d63a6. The affected component should be upgraded.
Which versions are affected by CVE-2026-90820?
How do I fix CVE-2026-90820?
No fix has been published for CVE-2026-90820 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-90820 being exploited?
There is no known exploitation of CVE-2026-90820 in the wild and no public exploit code.
Sources
Also known as GHSA-vmmr-97qx-h8c4.