CVE-2026-39889
Unauthorized Access in PraisonAI A2U Event Stream Server
Publication date: 2026-04-08
Last updated on: 2026-04-15
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| praison | praisonai | to 4.5.114 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-200 | The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
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.
How can this vulnerability impact me? :
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.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
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.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
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.
What immediate steps should I take to mitigate this vulnerability?
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.