CVE-2026-90820Network attack vectorHinoki check available

Task disclosure via unchecked list authorization

Published Sep 14, 2026 · Updated Sep 14, 2026

Missing authorization in A2A Java SDK 1.2.0 allows remote attackers to enumerate tasks through the server's List Tasks operation. AuthorizationRequestHandlerDecorator.onListTasks delegates task listing without a list-scoped read check, returning tasks outside the caller's authorization boundary. Network access to a deployed A2A server is sufficient, and the exposed data can include task status, context, message history, and artifacts.

CVSS severityUnavailable
Unscored
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Missing authorization in A2A Java SDK 1.2.0 allows remote attackers to enumerate tasks through the server's List Tasks operation. AuthorizationRequestHandlerDecorator.onListTasks delegates task listing without a list-scoped read check, returning tasks outside the caller's authorization boundary. Network access to a deployed A2A server is sufficient, and the exposed data can include task status, context, message history, and artifacts.

The record

CVE
CVE-2026-90820
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
A2A Project
Product
A2A Java SDK
Classifications
T1213
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

A2A Project · A2A Java SDKversion=1.2.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1213Data from Information Repositories

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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