5.3
MEDIUM CVSS 4.0
CVE-2026-90820
a2aproject a2a-java AuthorizationRequestHandlerDecorator.java AuthorizationRequestHandlerDecorator.onListTasks authorization
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.

INFO

Published Date :

Sept. 14, 2026, 9:17 p.m.

Last Modified :

Sept. 14, 2026, 9:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-90820 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 MEDIUM [email protected]
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Upgrade the affected component to version 1.3.0 to address the missing authorization vulnerability.
  • Upgrade to version 1.3.0.
  • Apply patch e9a1abf9c90c02b16d17293afdc3cc2f555d63a6.
  • Upgrade the affected component.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-90820 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-90820 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-90820 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-90820 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 14, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
    Added CVSS V2 (AV:N/AC:L/Au:S/C:P/I:N/A:N)
    Added CWE CWE-862
    Added CWE CWE-863
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90820.json">CVE-2026-90820</a>
    Added Reference https://github.com/a2aproject/a2a-java/
    Added Reference https://github.com/a2aproject/a2a-java/commit/e9a1abf9c90c02b16d17293afdc3cc2f555d63a6
    Added Reference https://github.com/a2aproject/a2a-java/pull/1038
    Added Reference https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final
    Added Reference https://vuldb.com/cve/CVE-2026-90820
    Added Reference https://vuldb.com/submit/925152
    Added Reference https://vuldb.com/vuln/403323
    Added Reference https://vuldb.com/vuln/403323/cti
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.