CVE-2026-55403 koxudaxi CVE debrief

Who should care

Defenders responsible for systems using the datamodel-code-generator package should assess exposure and prioritize upgrading to version 0.63.0 or later. The vulnerability impacts systems using the datamodel-code-generator package, particularly those with cross-origin redirects enabled. Defenders should review inventory of affected systems and verify if their systems use vulnerable versions of datamodel-code-generator.

Why it matters

CVE-2026-55403 is a vulnerability in datamodel-code-generator that allows credential leakage when following cross-origin redirects. Defenders should prioritize verifying exposure and upgrading to version 0.63.0 or later.

• Potential credential leakage when following cross-origin redirects
• Need to verify and upgrade to version 0.63.0 or later
• Possible exposure of sensitive information

Technical summary

The datamodel-code-generator package generates Python data models from schema definitions. Prior to version 0.63.0, the package's handling of cross-origin redirects while fetching remote schemas could lead to credential leakage. This issue was addressed in version 0.63.0. The vulnerability impacts systems using the datamodel-code-generator package, particularly those with cross-origin redirects enabled. Defenders should prioritize verifying if their systems use vulnerable versions of datamodel-code-generator and upgrading to version 0.63.0 or later.

Defensive priority

Defenders should prioritize verifying if their systems use vulnerable versions of datamodel-code-generator and upgrading to version 0.63.0 or later.

Recommended defensive actions

• Verify if systems use vulnerable versions of datamodel-code-generator
• Upgrade to version 0.63.0 or later
• Review and update inventory of affected systems
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• 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

Evidence notes

The CVE record and NVD entry provide details about the vulnerability, its impact, and the fixed version. However, there is limited information about potential exploitation or affected systems. Defenders should verify if their systems use vulnerable versions of datamodel-code-generator and review inventory of affected systems. The vulnerability allows credential leakage when following cross-origin redirects, and defenders should prioritize verifying exposure and upgrading to version 0.63.0 or later.

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.