CVE-2026-90790

Deferred Deferred - Pending Action

Server-Side Request Forgery in a2a-python Push Notification Sender

Publication date: 2026-09-14

Last updated on: 2026-09-15

Assigner: VulDB

Description

A security vulnerability has been detected in a2aproject a2a-python up to 1.1.3. This affects the function _dispatch_notification of the file src/a2a/server/tasks/base_push_notification_sender.py of the component Push Notification Sender. The manipulation of the argument push_info.url leads to server-side request forgery. Remote exploitation of the attack is possible. Upgrading to version 1.1.4 is able to mitigate this issue. It is suggested to upgrade the affected component.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-14

Last Modified

2026-09-15

Generated

2026-09-15

AI Q&A

2026-09-14

EPSS Evaluated

N/A

NVD

CVE-2026-90790

EUVD

EUVD-2026-77535

Affected Vendors & Products

Vendor	Product	Version / Range
a2aproject	a2a-python	to 1.1.3 (inc)
a2aproject	a2a-python	to 1.1.4 (exc)
a2aproject	a2a-python	1.1.4

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

Executive Summary

CVE-2026-90790 is a Server-Side Request Forgery (SSRF) vulnerability in the a2a-python project up to version 1.1.3. It occurs in the _dispatch_notification function of base_push_notification_sender.py where unvalidated push-notification URLs are used in HTTP POST requests. Attackers can manipulate the push_info.url argument to direct the server to send requests to internal or restricted addresses like localhost or cloud metadata endpoints.

Detection Guidance

To detect this SSRF vulnerability in a2a-python, monitor network traffic for outbound requests from the server to internal or restricted addresses like localhost, 169.254.169.254, or private network ranges. Check logs for failed push-notification dispatch attempts or validation errors in src/a2a/server/tasks/base_push_notification_sender.py.

Impact Analysis

This vulnerability allows attackers to make unauthorized requests from your server to internal or sensitive targets. This could expose internal services, metadata endpoints, or private network resources. Attackers might access sensitive data, interact with internal APIs, or perform actions on behalf of your server, potentially leading to data breaches or further network compromise.

Compliance Impact

This SSRF vulnerability could lead to unauthorized access to sensitive data or systems, violating confidentiality requirements under GDPR and HIPAA. It may result in data breaches, unauthorized disclosure of personal health information, or other protected data, potentially leading to regulatory penalties, fines, or legal consequences for non-compliance.

Mitigation Strategies

Upgrade to a2a-python version 1.1.4 or later, which includes URL validation to prevent SSRF. Ensure push-notification URLs are validated to block private, loopback, link-local, and cloud metadata endpoints. Disable redirect-following in clients and review push-notification configurations for suspicious URLs.

Hi! I’m here to help you understand CVE-2026-90790. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70