CVE-2026-57112 in PraisonAI
Summary
by MITRE • 09/15/2026
PraisonAI is a multi-agent teams system. From praisonaiagents 0.6.0 until 1.6.59 and PraisonAI 3.10.0 until 4.6.59, ToolsMCPServer.run_sse() in src/praisonai-agents/praisonaiagents/mcp/mcp_server.py mounts SseServerTransport on the legacy /sse and /messages/ endpoints without default Host, Origin, or authentication enforcement. A malicious website can use DNS rebinding against a reachable local or internal SSE server, supply attacker-controlled Host and Origin headers, enumerate registered tools, and invoke them with the server user's privileges. The Streamable HTTP transport rejects the same hostile Origin, which isolates the flaw to the legacy SSE wrapper. An initial remediation was released in praisonaiagents 1.6.59 and PraisonAI 4.6.59.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified within PraisonAI involves a critical misconfiguration in its Multi-Agent Teams system, specifically affecting versions of the praisonai-agents library from 0.6.0 through 1.6.59 and the PraisonAI application from 3.10.0 through 4.6.59. The core technical flaw resides within the ToolsMCPServer.run_sse() method located in the source file src/praisonai-agents/praisonaiagents/mcp/mcp_server.py. This component implements a legacy Server-Sent Events (SSE) transport mechanism that fails to enforce standard security controls, most notably default Host and Origin header validation as well as authentication requirements. By mounting the SseServerTransport on the /sse and /messages/ endpoints without these safeguards, the system inadvertently exposes internal tools to external actors who can manipulate HTTP headers to bypass intended access restrictions.
The operational impact of this vulnerability is severe due to its susceptibility to DNS rebinding attacks. A malicious website hosted by an attacker can exploit this flaw against a reachable local or internal SSE server running PraisonAI. Through DNS rebinding, the attacker tricks the victim's browser into sending requests that appear to originate from the trusted local domain while actually being served from the attacker’s remote infrastructure. Because the legacy SSE wrapper does not validate the Origin header, it accepts these hostile headers as legitimate. This allows an unauthenticated external actor to enumerate registered tools available on the server and subsequently invoke them with the privileges of the user running the PraisonAI instance. Consequently, this can lead to unauthorized access to sensitive data, execution of arbitrary commands within the context of the application’s environment, or further lateral movement if internal services are exposed through these tool invocations.
This vulnerability is distinct from other transport mechanisms used by PraisonAI because the Streamable HTTP transport correctly rejects hostile Origin headers, thereby isolating the flaw strictly to the legacy SSE wrapper implementation. This discrepancy highlights a common issue in software development where older or less frequently maintained code paths lack the rigorous security checks present in newer implementations. The absence of authentication enforcement on these endpoints further exacerbates the risk, as it allows any entity capable of performing DNS rebinding to interact with the system without providing valid credentials.
To mitigate this vulnerability, organizations must upgrade immediately to praisonai-agents version 1.6.59 or PraisonAI version 4.6.59 and later, where an initial remediation has been released. These updates address the lack of header validation and authentication enforcement in the legacy SSE transport. For systems that cannot be upgraded immediately, network-level controls such as firewall rules restricting access to ports used by PraisonAI should be implemented to prevent external DNS rebinding attempts from reaching the vulnerable endpoints. Additionally, disabling or removing the legacy /sse and /messages/ endpoints if they are not strictly required for operation can reduce the attack surface. Security teams should also monitor logs for unusual patterns of requests originating from unexpected origins or involving tool enumeration activities that may indicate an active exploitation attempt.
From a classification perspective, this vulnerability aligns with CWE-346, which describes the origin validation error in security features, and CWE-287, relating to improper authentication mechanisms. In terms of adversary tactics, it facilitates techniques associated with ATT&CK ID T1071, specifically application layer protocols used for command and control or data exfiltration by leveraging trusted domains through DNS rebinding. The combination of missing origin validation and lack of authentication creates a pathway that allows attackers to abuse legitimate system functions for unauthorized purposes, underscoring the importance of consistent security enforcement across all transport layers within complex multi-agent systems.