CVE-2026-55529

PraisonAI: Origin validation bypass in MCP HTTP Stream transport allows browser-mediated unauthenticated tool execution on local MCP server

State: Published
Severity: 6.9 Medium
Published: Aug 25, 2026
Updated: Aug 27, 2026
Reserved: Jun 16, 2026

Read the record on cve.org

Description

PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, the MCP HTTP Stream _validate_origin method accepts request_origin.startswith(allowed), so the attacker-controlled localhost.evil.example HTTP origin matches the localhost allowlist. Without an API key, a malicious webpage can submit tools/call requests to the local MCP server and execute exposed tools. This issue is fixed in version 4.6.58.

Scores

CVSS	Score	Vector	Source
3.1	6.9 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N	GitHub_M

Weaknesses

CWE-306 Missing Authentication for Critical Function
CWE-346 Origin Validation Error

Affected Products

Product	Versions
PraisonAIMervinPraison	< 4.6.58Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.