CVE-2026-58497 olo-dot-io CVE debrief

Who should care

Defenders responsible for Uni-CLI deployments should assess exposure and prioritize upgrading to version 0.225.2 or later. If immediate upgrade is not possible, they should ensure the legacy HTTP MCP transport is not exposed to browser-originated requests.

Why it matters

CVE-2026-58497 allows malicious web pages to potentially drive requests against the user's local Uni-CLI server if the legacy HTTP MCP transport is exposed. Defenders should prioritize upgrading to version 0.225.2 or later and ensure the transport is not exposed unnecessarily.

• Potential for malicious web pages to drive tools/call requests against the user's local Uni-CLI server
• Exposure of the legacy HTTP MCP transport to browser-originated requests
• Need for defenders to verify and update configurations to prevent exploitation
• Priority for upgrading to Uni-CLI version 0.225.2 or later

Technical summary

The Uni-CLI's legacy HTTP MCP transport did not validate browser Origin headers before routing requests, allowing malicious web pages to send CORS simple POST requests to the local /mcp endpoint. This issue was patched in version 0.225.2 by moving the Origin policy into a shared guard and applying it before routing in both HTTP transports. The vulnerability allowed malicious web pages to potentially drive tools/call requests against the user's local Uni-CLI server if the local MCP HTTP transport was started. Defenders should prioritize upgrading to Uni-CLI version 0.225.2 or later to address the vulnerability.

Defensive priority

Defenders should prioritize upgrading to Uni-CLI version 0.225.2 or later to address the vulnerability. If immediate upgrade is not possible, do not expose the legacy HTTP MCP transport to browser-originated requests.

Recommended defensive actions

• Upgrade to Uni-CLI version 0.225.2 or later
• If upgrading is not immediately possible, do not expose the legacy HTTP MCP transport to browser-originated requests
• Review and update configurations to ensure the legacy HTTP MCP transport is not exposed unnecessarily
• Confirm whether affected Uni-CLI deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source item provide details on the vulnerability, its impact, and the patch. The vulnerability was publicly disclosed on 2026-06-19T21:43:09.000Z. The source item provides additional context on the issue, including the affected versions and the fix.

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.