CVE-2026-39889
Undergoing Analysis Undergoing Analysis - In Progress
Unauthorized Access in PraisonAI A2U Event Stream Server

Publication date: 2026-04-08

Last updated on: 2026-04-15

Assigner: GitHub, Inc.

Description
PraisonAI is a multi-agent teams system. Prior to 4.5.115, the A2U (Agent-to-User) event stream server in PraisonAI exposes all agent activity without authentication. The create_a2u_routes() function registers the following endpoints with NO authentication checks: /a2u/info, /a2u/subscribe, /a2u/events/{stream_name}, /a2u/events/sub/{id}, and /a2u/health. This vulnerability is fixed in 4.5.115.
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Meta Information
Published
2026-04-08
Last Modified
2026-04-15
Generated
2026-06-16
AI Q&A
2026-04-09
EPSS Evaluated
2026-06-15
NVD
CVE-2026-39889
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
praison praisonai to 4.5.114 (inc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-200 The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
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Detection Guidance

The vulnerability involves unauthenticated access to specific endpoints on the PraisonAI A2U event stream server prior to version 4.5.115. To detect if your system is vulnerable, you can attempt to access the following endpoints without authentication:

  • /a2u/info
  • /a2u/subscribe
  • /a2u/events/{stream_name}
  • /a2u/events/sub/{id}
  • /a2u/health

You can use tools like curl or wget to test these endpoints. For example, to check the /a2u/info endpoint, you can run the command: curl -i http://<target-host>/a2u/info If the response returns data without requiring authentication, the system is likely vulnerable.

Executive Summary

The vulnerability in PraisonAI affects the A2U (Agent-to-User) event stream server prior to version 4.5.115. Specifically, several endpoints related to agent activity (/a2u/info, /a2u/subscribe, /a2u/events/{stream_name}, /a2u/events/sub/{id}, and /a2u/health) are exposed without any authentication checks. This means that anyone can access these endpoints and view all agent activity without needing to log in or prove their identity.

Impact Analysis

This vulnerability can lead to unauthorized disclosure of sensitive information because it allows unauthenticated users to access all agent activity data. Since the CVSS score indicates a high impact on confidentiality (C:H), attackers could potentially gather sensitive or private information from the exposed endpoints. However, the vulnerability does not affect integrity or availability.

Compliance Impact

This vulnerability exposes all agent activity without authentication, potentially leading to unauthorized access to sensitive information.

Such unauthorized exposure could result in non-compliance with data protection regulations like GDPR and HIPAA, which require strict access controls and protection of personal and sensitive data.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade PraisonAI to version 4.5.115 or later, where the issue is fixed.

Until the upgrade is applied, restrict access to the A2U event stream server endpoints (/a2u/info, /a2u/subscribe, /a2u/events/{stream_name}, /a2u/events/sub/{id}, and /a2u/health) by implementing network-level controls such as firewall rules or access control lists to prevent unauthorized access.

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