CVE-2026-55391 koxudaxi CVE debrief

Who should care

Users of datamodel-code-generator, especially those with exposure to internal services, should be aware of this vulnerability and take immediate action to patch their installations. This includes verifying if datamodel-code-generator is used in the environment, applying the patch, and monitoring for suspicious activity. Operators, platform administrators, vulnerability management teams, and security teams should review the vulnerability and take necessary actions to protect their systems. Datamodel-code-generator users should also verify their inventory and apply the patch to prevent potential DNS rebinding attacks. Additionally, users should implement monitoring to detect potential DNS rebinding attacks and review compensating controls for exposed systems while remediation is scheduled and verified. Exceptions, retest remediated assets, and close the item only after evidence is documented. Track relevant monitoring, detection, and logs for exposed assets that need extra review. Confirm whether affected product 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. Track exceptions, retest remediated assets, and close the item only after evidence is documented. Review compensating controls for exposed systems while remediation is scheduled and verified. Implement monitoring to detect potential DNS rebinding attacks. Verify if datamodel-code-generator is used in your environment. Apply patch: Upgrade to datamodel-code-generator version 0.63.0 or later. Monitor for suspicious activity: Implement monitoring to detect potential DNS rebinding attacks. Inventory check: Verify if datamodel-code-generator is used in your environment. Compensating controls: Review compensating controls for exposed systems while remediation is scheduled and verified. Asset inventory: Verify if datamodel-code-generator is used in your environment. Rollback/change: Plan

Technical summary

CVE-2026-55391 is a high-severity vulnerability in datamodel-code-generator that allows for DNS rebinding attacks. The issue was patched in version 0.63.0. The vulnerability has a CVSS score of 7.5 and can be exploited by attackers to bypass network restrictions and access internal services. The vulnerability is caused by duplicate host validation in datamodel-code-generator versions before 0.63.0.

Defensive priority

High-priority defensive review required for datamodel-code-generator users, especially those with exposure to internal services.

Recommended defensive actions

• Inventory check: Verify if datamodel-code-generator is used in your environment.
• Apply patch: Upgrade to datamodel-code-generator version 0.63.0 or later.
• Monitor for suspicious activity: Implement monitoring to detect potential DNS rebinding attacks.
• Confirm whether affected product 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.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE-2026-55391 issue allows for DNS rebinding attacks due to duplicate host validation in datamodel-code-generator versions before 0.63.0. Users should verify their inventory and apply the patch. Evidence is based on official CVE and NVD records, as well as vendor advisories.

Official resources