GitHub Advisoryadvisory · PyPI

GHSA-f292-66h9-fpmf PraisonAI Has Unauthenticated SSE Event Stream that Exposes All Agent Activity in A2U Server

HIGH Published 2026-04-08 Modified 2026-04-09 Official page ↗
Aliases
CVE-2026-39889
Ecosystem
PyPI
Packages
praisonai
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
CWE-200
Reviewed
2026-04-08

Affected packages

• PyPI praisonai: < 4.5.115 → fixed in 4.5.115

Description

The A2U (Agent-to-User) event stream server in PraisonAI exposes all agent activity without authentication. This is a separate component from the gateway server fixed in CVE-2026-34952. The create_a2u_routes() function registers the following endpoints with NO authentication checks: • GET /a2u/info — exposes server info and stream names • POST /a2u/subscribe — creates event stream subscription • GET /a2u/events/{stream_name} — streams ALL agent events • GET /a2u/events/sub/{id} — streams events for subscription • GET /a2u/health — health check An unauthenticated attacker can: 1. POST /a2u/subscribe → receive subscription_id 2. GET /a2u/events/sub/{subscription_id} → receive live SSE stream of all agent events including responses, tool calls, and thinking This exposes sensitive agent activity including responses, internal reasoning, and tool call arguments to any network attacker. [1] POST /a2u/subscribe (no auth token) Status: 200 Response: {"subscription_id":"sub-a1ad8a6edd8b","stream_name":"events", "stream_url":"http://testserver/a2u/events/sub-a1ad8a6edd8b"} Got subscription_id: sub-a1ad8a6edd8b [2] GET /a2u/info (no auth token) Status: 200 Response: {"name":"A2U Event Stream","version":"1.0.0", "streams":["events"],"event_types":["agent.started","agent.thinking", "agent.tool_call","agent.response","agent.completed","agent.error"]} [3] GET /a2u/health (no auth token) Status: 200 Response: {"status":"healthy","active_subscriptions":1,"active_streams":1} Impact: Attacker can subscribe and receive ALL agent events including responses, tool calls, and internal reasoning in real-time

Related

Alias · CVE (1)

  • CVE-2026-39889 PraisonAI is a multi-agent teams system. vulnerability

Weakness · CWE (1)

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness

References