CVE-2026-40289: PraisonAI is a multi-agent teams system. In versions below 4.5.139 of PraisonAI and 1.5.140 of praisonaiagents, the browser bridge (praisonai browser start) is…

PriorityP261critical9.1CVSS 3.1

AVNACLPRNUINSUCHIHAN

EPSS

0.36%

27.5th percentile

PraisonAI is a multi-agent teams system. In versions below 4.5.139 of PraisonAI and 1.5.140 of praisonaiagents, the browser bridge (praisonai browser start) is vulnerable to unauthenticated remote session hijacking due to missing authentication and a bypassable origin check on its /ws WebSocket endpoint. The server binds to 0.0.0.0 by default and only validates the Origin header when one is present, meaning any non-browser client that omits the header is accepted without restriction. An unauthenticated network attacker can connect, send a start_session message, and the server will route it to the first idle browser-extension WebSocket (effectively hijacking that session) and then broadcast all resulting automation actions and outputs back to the attacker. This enables unauthorized remote control of connected browser automation sessions, leakage of sensitive page context and automation results, and misuse of model-backed browser actions in any environment where the bridge is network-reachable. This issue has been fixed in versions 4.5.139 of PraisonAI and 1.5.140 of praisonaiagents.

Affected

6 ranges

Vendor	Product	Version range	Fixed in
mervinpraison	praisonai	< 4.5.139	4.5.139
mervinpraison	praisonai	>= 0 < 4.5.139	4.5.139
mervinpraison	praisonaiagents	< 1.5.140	1.5.140
mervinpraison	praisonaiagents	>= 0 < 1.5.140	1.5.140
praison	praisonai	< 4.5.139	4.5.139
praison	praisonaiagents	< 1.5.140	1.5.140

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