PatchSiren cyber security CVE debrief
CVE-2026-49257 startreedata CVE debrief
A critical vulnerability was discovered in mcp-pinot, a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. The vulnerability allows for full read/write access to the configured Pinot cluster due to a confused-deputy condition. This condition arises because mcp-pinot defaults to running an HTTP MCP server bound to 0.0.0.0:8080 with no authentication enabled, allowing all MCP tools, including SQL query execution, schema creation, and table-config mutation, to be reachable by any network-adjacent caller. The server proxies these calls using server-side Pinot credentials, producing the confused-deputy condition that yields full read/write access to the configured Pinot cluster.
- Vendor
- startreedata
- Product
- mcp-pinot
- CVSS
- CRITICAL 10
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-18
- Original CVE updated
- 2026-06-23
- Advisory published
- 2026-06-18
- Advisory updated
- 2026-06-23
Who should care
Users of mcp-pinot versions 3.0.1 and below should apply the patch to prevent exploitation. This includes operators of Apache Pinot clusters who use mcp-pinot for interactions with the cluster, as well as security teams and vulnerability management teams responsible for ensuring the security of these systems.
Technical summary
mcp-pinot defaults to running an HTTP MCP server bound to 0.0.0.0:8080 with no authentication enabled, allowing all MCP tools, including SQL query execution, schema creation, and table-config mutation, to be reachable by any network-adjacent caller. The server proxies these calls using server-side Pinot credentials, producing a confused-deputy condition that yields full read/write access to the configured Pinot cluster. This issue has been fixed in version 3.1.0.
Defensive priority
High
Recommended defensive actions
- Apply the patch to upgrade to version 3.1.0
- Disable the HTTP MCP server or restrict access to it
- Monitor for suspicious activity on the Pinot cluster
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
The CVE record was published on 2026-06-18T21:16:29.780Z and has been modified since then. The NVD entry is currently Deferred. Evidence is limited to public sources and may not reflect the full scope or impact of the vulnerability. Defenders should verify affected systems and apply patches or mitigations as needed.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-06-18T21:16:29.780Z and has been modified since then. The NVD entry is currently Deferred.