CVE-2026-81095 timescale CVE debrief

Who should care

Defenders responsible for systems using pg-aiguide should assess exposure and prioritize verification and remediation. This includes reviewing system configurations and inventory for potential exposure, monitoring for suspicious activity, and implementing compensating controls as needed. The vulnerability's operational impacts include verifying and updating the pg-aiguide dependency, assessing system configurations, and monitoring for suspicious activity.

Why it matters

CVE-2026-81095 allows DNS rebinding attacks due to pg-aiguide's MCP HTTP transport configuration. Defenders should verify and update the dependency, assess system exposure, and monitor for suspicious activity.

• Verify and update pg-aiguide dependency to prevent DNS rebinding attacks
• Assess system configurations and inventory for potential exposure
• Monitor for suspicious activity and implement compensating controls as needed

Technical summary

The pg-aiguide library started its MCP HTTP transport without enabling the host allow-list provided by the underlying SDK, allowing DNS rebinding attacks. This was fixed in version 0.5.1 by explicitly passing the DNS-rebinding-protection option. The vulnerability allows an attacker to drive the locally reachable MCP server through the visitor's browser by pointing a controlled name at the address the server is bound to. Defenders should prioritize verifying and updating the pg-aiguide dependency to version 0.5.1 or later.

Defensive priority

Defenders should prioritize verifying and updating the pg-aiguide dependency to version 0.5.1 or later.

Recommended defensive actions

• Verify the pg-aiguide dependency version and update to 0.5.1 or later
• Review system configurations and inventory for potential exposure
• Monitor for suspicious activity and implement compensating controls as needed
• Assess system configurations and inventory for potential exposure
• Implement compensating controls for exposed systems
• Track exceptions and retest remediated assets
• Review relevant monitoring, detection, and logs for exposed assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but the scope of affected versions and systems requires further verification. Defenders should verify the pg-aiguide dependency version and update to 0.5.1 or later, review system configurations and inventory for potential exposure, and monitor for suspicious activity. The vulnerability allows DNS rebinding attacks due to the MCP HTTP transport configuration.

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.