CVE-2026-49471 oraios CVE debrief

Who should care

Users of Serena MCP toolkit versions prior to v1.5.2 should update to v1.5.2 to prevent potential remote code execution attacks. This includes operators of systems where Serena is deployed, as well as security and vulnerability management teams responsible for ensuring the security of these systems. Additionally, platform administrators and security teams should review the configuration and exposure of Serena in their environments.

Technical summary

Serena's built-in web dashboard exposes an unauthenticated Flask API on a fixed, predictable port, with no authentication, no CSRF protection, and no Host header validation. A DNS rebinding attack allows a malicious webpage to reach this API from any browser and write arbitrary content to the agent's persistent memory store, which the agent reads and acts on autonomously. Combined with execute_shell_command using shell=True, this creates a remote code execution chain requiring only that the victim visit a malicious webpage while Serena is running.

Defensive priority

High priority due to high CVSS score of 8.3 and potential for remote code execution.

Recommended defensive actions

• Update Serena to version v1.5.2 or later
• Restrict access to the Serena web dashboard
• Implement authentication and CSRF protection for the Flask API
• Monitor for suspicious activity and implement compensating controls
• Review network exposure and implement firewall rules to restrict access to the Serena API
• Perform a thorough review of system configurations and ensure that execute_shell_command is not used with shell=True
• Track exceptions and retest remediated assets to ensure the vulnerability is fully resolved

Evidence notes

Evidence is limited to the supplied source corpus. Further investigation is needed to determine the full scope of the vulnerability and potential affected systems. The Serena MCP toolkit's built-in web dashboard exposes an unauthenticated Flask API on a fixed, predictable port. A DNS rebinding attack allows a malicious webpage to reach this API from any browser and write arbitrary content to the agent's persistent memory store. The agent reads and acts on this content autonomously, which can lead to remote code execution if combined with execute_shell_command using shell=True. Defenders should verify the presence of Serena in their environment, review network exposure, and implement compensating controls.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.