What’s Vulnerable › Vulnerabilities

CVE-2026-55529: PraisonAI: Origin validation bypass in MCP HTTP Stream transport allows browser-mediated unauthenticated tool execution on local MCP server

• Severity: medium (CVSS 6.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-25 · updated 2026-09-09
• Weakness: CWE-306

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.

Affected products

• MervinPraison PraisonAI: before 4.6.58

References

• https://github.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1
• https://github.com/MervinPraison/PraisonAI/releases/tag/v4.6.58
• https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-wj6g-v78p-6fx3
• https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-wj6g-v78p-6fx3

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