Authorization Flaw in a2aproject a2a-java Affects Remote Security
CVE-2026-90820

5.3MEDIUM

Key Information:

Vendor

A2aproject

Status
A2a-java
Vendor
CVE Published:
14 September 2026

What is CVE-2026-90820?

A critical security flaw has been identified in the a2a-java product, specifically within the AuthorizationRequestHandlerDecorator.onListTasks function. This vulnerability allows remote attackers to bypass authorization checks, potentially leading to unauthorized access. Users are strongly encouraged to upgrade to version 1.3.0 to mitigate this risk. The corresponding patch for this issue can be found under commit e9a1abf9c90c02b16d17293afdc3cc2f555d63a6.

Affected Version(s)

a2a-java 1.2.0

a2a-java 1.3.0

References

https://vuldb.com/vuln/403323
vdb-entrytechnical-description
https://vuldb.com/vuln/403323/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-90820
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

colorfullbz (VulDB User)
.